Mr. A wants to get to the destination on the Yamanote line.

After getting on the train, Mr. A gets up for a minute and sleeps for b minutes repeatedly. It is c minutes after boarding to the destination, and you can get off if you are awake at this time, but on the contrary, if you are sleeping, you will miss it. Also, Mr. A will continue to take the same train even if he overtakes it, and the train will take 60 minutes to go around the Yamanote line. Therefore, Mr. A will arrive at the destination after 60t + c (t is a non-negative integer) minutes.

How many minutes will A be able to reach his destination? Output -1 when it is unreachable. However, if the time you arrive at your destination is the boundary between the time you are sleeping and the time you are awake, you can get off.

Constraints

* 0 <a, b, c <60

Input

The input is given in one line in the following format.


a b c


The input consists of three integers a, b, c.

a is the time you are awake, b is the time you are sleeping, and c is the time it takes to get to your destination after boarding. The unit of a, b, and c is minutes.

Output

If you can reach your destination, output the time it takes to reach your destination. Otherwise, output -1.

Examples

Input

10 10 5


Output

5


Input

50 40 51


Output

111


Input

20 20 20


Output

20


Input

30 30 40


Output

-1
import java.awt.geom.Point2D;
import java.io.IOException;
import java.io.InputStream;
import java.util.*;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.function.Supplier;

public class Main {
  final static int INF = 1 << 28;
  final static long MOD = 1_000_000_007;
  final static double EPS = 1e-9;
  final static double GOLDEN_RATIO = (1.0 + Math.sqrt(5)) / 2.0;
  Scanner sc = new Scanner(System.in);

  public static void main(String[] args) {
    new Main().run();
  }

  void run() {
    int a, b, c;
    a = ni();
    b = ni();
    c = ni();
    int t = 0;
    int ans = -1;
    for (int i = 0; i <= 3600; ++i) {
      int s = t;
      t += a;
      if (s <= c && c <= t) {
        ans = (a + b) * i + c - s;
        break;
      }
      t += b;
      t %= 60;
    }
    System.out.println(ans);
  }

  int ni() {
    return Integer.parseInt(sc.next());
  }

  void debug(Object... os) {
    System.err.println(Arrays.deepToString(os));
  }

  /**
   * ??????????????????????????????
   *
   * @return a ??¨ b ????????§??¬?´???°
   */
  long gcd(long a, long b) {
    if (b == 0) {
      return a;
    }
    return gcd(b, a % b);
  }

  /**
   * ????????????????????????????????????
   *
   * @return mx + ny = gcd(m, n)??¨???????????????(x, y)?????????
   */
  Pair<Long, Long> gcd_ex(long m, long n) {
    long[][] mat = _gcd_ex(m, n);
    return new Pair<>(mat[0][0], mat[0][1]);
  }

  long[][] _gcd_ex(long m, long n) {
    if (n == 0) {
      return new long[][]{{1, 0}, {0, 1}};
    }
    long k = m / n;
    long[][] K = new long[][]{{0, 1}, {1, -k}};
    long[][] r = _gcd_ex(n, m % n);
    long[][] dst = new long[2][2];
    for (int y = 0; y < 2; ++y)
      for (int x = 0; x < 2; ++x)
        for (int i = 0; i < 2; ++i)
          dst[y][x] += r[y][i] * K[i][x];
    return dst;
  }

  /**
   * ??°?????????2???????????¨??????????????????????£?
   *
   * @return a^r (mod 1,000,000,007)
   */
  long pow(long a, long r) {
    long sum = 1;
    while (r > 0) {
      if ((r & 1) == 1) {
        sum *= a;
        sum %= MOD;
      }
      a *= a;
      a %= MOD;
      r >>= 1;
    }
    return sum;
  }

  /**
   * ???????????????
   * O(n)
   *
   * @return {}_nC_r
   */
  long C(int n, int r) {
    long sum = 1;
    for (int i = n; 0 < i; --i) {
      sum *= i;
      sum %= MOD;
    }
    long s = 1;
    for (int i = r; 0 < i; --i) {
      s *= i;
      s %= MOD;
    }
    sum *= pow(s, MOD - 2);
    sum %= MOD;

    long t = 1;
    for (int i = n - r; 0 < i; --i) {
      t *= i;
      t %= MOD;
    }
    sum *= pow(t, MOD - 2);
    sum %= MOD;

    return sum;
  }

  /**
   * ??????????????¢?´¢
   *
   * @param left  ??????
   * @param right ??????
   * @param f     ??¢?´¢????????¢??°
   * @param comp  ??????????????¢??°?????¢?´¢????????¨?????????Comparator.comparingDouble(Double::doubleValue)
   *              ??????????????¢??°?????¢?´¢????????¨?????????Comparator.comparingDouble(Double::doubleValue).reversed()
   * @return ?\?????????§?¨?x
   */
  double goldenSectionSearch(double left, double right, Function<Double, Double> f, Comparator<Double> comp) {
    double c1 = divideInternally(left, right, 1, GOLDEN_RATIO);
    double c2 = divideInternally(left, right, GOLDEN_RATIO, 1);
    double d1 = f.apply(c1);
    double d2 = f.apply(c2);
    while (right - left > 1e-9) {
      if (comp.compare(d1, d2) > 0) {
        right = c2;
        c2 = c1;
        d2 = d1;
        c1 = divideInternally(left, right, 1, GOLDEN_RATIO);
        d1 = f.apply(c1);
      } else {
        left = c1;
        c1 = c2;
        d1 = d2;
        c2 = divideInternally(left, right, GOLDEN_RATIO, 1);
        d2 = f.apply(c2);
      }
    }
    return right;
  }

  /**
   * [a,b]???m:n???????????????????????????
   */
  double divideInternally(double a, double b, double m, double n) {
    return (n * a + m * b) / (m + n);
  }

  /**
   * http://alexbowe.com/popcount-permutations/
   * bit????????£???????????°????°?????????????????????????????????¨???????????????
   * ex)
   * <pre>
   * for (int i = 0; i < 25; ++i) {
   *   int bits = (1 << i) - 1;
   *   long m = C(25, num);
   *   for (j = 0; j < m; ++j) {
   *     ...(25???????????????i???bit????????£?????????)
   *     if (bits != 0)
   *       bits = next_perm(bits);
   *   }
   * }
   * </pre>
   *
   * @param v ?????¨???bit???
   * @return ?¬????bit???
   */
  int next_perm(int v) {
    int t = (v | (v - 1)) + 1;
    return t | ((((t & -t) / (v & -v)) >> 1) - 1);
  }

  /**
   * from http://gihyo.jp/dev/serial/01/geometry part 6
   */
  static class Line {
    double a;
    double b;
    double c;

    /**
     * ?????¬??¢??????????????????????????´??????????????????
     *
     * @param a x????????°
     * @param b y????????°
     * @param c ?????°???
     */
    Line(double a, double b, double c) {
      this.a = a;
      this.b = b;
      this.c = c;
    }

    /**
     * 2???(x1, y1), (x2, y2)???????????´??????????????????
     *
     * @param x1 1?????????x??§?¨?
     * @param y1 1?????????y??§?¨?
     * @param x2 2?????????x??§?¨?
     * @param y2 2?????????y??§?¨?
     * @return ??´???
     */
    static Line fromPoints(double x1, double y1, double x2, double y2) {
      double dx = x2 - x1;
      double dy = y2 - y1;
      return new Line(dy, -dx, dx * y1 - dy * x1);
    }

    /**
     * ?????????????????´?????¨??????????????????
     *
     * @param l ??´???
     * @return ?????????2??´?????????????????´??????null
     */
    Point2D getIntersectionPoint(Line l) {
      double d = a * l.b - l.a * b;
      if (d == 0.0) {
        return null;
      }
      double x = (b * l.c - l.b * c) / d;
      double y = (l.a * c - a * l.c) / d;
      return new Point2D.Double(x, y);
    }

    @Override
    public String toString() {
      return "a = " + a + ", b = " + b + ", c = " + c;
    }
  }

  /**
   * from http://gihyo.jp/dev/serial/01/geometry part 6
   */
  static public class LineSegment {
    double x1;
    double y1;
    double x2;
    double y2;

    LineSegment(double x1, double y1, double x2, double y2) {
      this.x1 = x1;
      this.y1 = y1;
      this.x2 = x2;
      this.y2 = y2;
    }

    Line toLine() {
      return Line.fromPoints(x1, y1, x2, y2);
    }

    boolean intersects(Line l) {
      double t1 = l.a * x1 + l.b * y1 + l.c;
      double t2 = l.a * x2 + l.b * y2 + l.c;
      return t1 * t2 <= 0;
    }

    boolean intersects(LineSegment s) {
      return bothSides(s) && s.bothSides(this);
    }

    // s???????????????????????´????????????????????????????????????
    private boolean bothSides(LineSegment s) {
      double ccw1 = GeomUtils.ccw(x1, y1, s.x1, s.y1, x2, y2);
      double ccw2 = GeomUtils.ccw(x1, y1, s.x2, s.y2, x2, y2);
      if (ccw1 == 0 && ccw2 == 0) { // s??¨?????????????????´?????????????????´???
        // s???????????????1???????????????????????????????????????????????°???s??????????????¨??±?????¨?????????????????§
        // true?????????
        return internal(s.x1, s.y1) || internal(s.x2, s.y2);
      } else { // ????????\????????´???
        // CCW???????¬?????????°????????´??????true?????????
        return ccw1 * ccw2 <= 0;
      }
    }

    // (x, y)?????????????????????????????????????????????????????????
    private boolean internal(double x, double y) {
      // (x, y)????????????????????????????????????????????????????????\?????§????????°????????¨?????????
      return GeomUtils.dot(x1 - x, y1 - y, x2 - x, y2 - y) <= 0;
    }

    public Point2D getIntersectionPoint(Line l) {
      if (!intersects(l)) {
        return null; // ?????????????????´??????null?????????
      }
      return l.getIntersectionPoint(toLine());
    }

    public Point2D getIntersectionPoint(LineSegment s) {
      if (!intersects(s)) {
        return null; // ?????????????????´??????null?????????
      }
      return s.toLine().getIntersectionPoint(toLine());
    }

    /**
     * from : http://www.deqnotes.net/acmicpc/2d_geometry/lines#distance_between_line_segment_and_point
     */
    double distance(double x0, double y0) {
      // ???????????§??????
      if (GeomUtils.dot(x2 - x1, y2 - y1, x0 - x1, y0 - y1) < EPS) {
        return GeomUtils.abs(x0 - x1, y0 - y1);
      }
      if (GeomUtils.dot(x1 - x2, y1 - y2, x0 - x2, y0 - y2) < EPS) {
        return GeomUtils.abs(x0 - x2, y0 - y2);
      }
      // ??´?????¨???????????¢
      return Math.abs(GeomUtils.cross(x2 - x1, y2 - y1, x0 - x1, y0 - y1)) / GeomUtils.abs(x2 - x1, y2 - y1);
    }

    double distance(LineSegment l) {
      if (this.intersects(l)) {
        return 0.0;
      }
      double min = Double.MAX_VALUE;
      min = Math.min(min, distance(l.x1, l.y1));
      min = Math.min(min, distance(l.x2, l.y2));
      min = Math.min(min, l.distance(x1, y1));
      min = Math.min(min, l.distance(x2, y2));
      return min;
    }

    @Override
    public String toString() {
      return "(" + x1 + ", " + y1 + ") - (" + x2 + ", " + y2 + ")";
    }
  }

  /**
   * from http://gihyo.jp/dev/serial/01/geometry part 6
   */
  static class GeomUtils {
    static double cross(double x1, double y1, double x2, double y2) {
      return x1 * y2 - x2 * y1;
    }

    static double dot(double x1, double y1, double x2, double y2) {
      return x1 * x2 + y1 * y2;
    }

    // (x1, y1) -> (x2, y2) -> (x3, y3) ??¨?????????????????????????¨????????????´????????£?????????
    // ????¨????????????´???????????????????????´???????????´?????????????????????
    static double ccw(double x1, double y1, double x2, double y2,
                      double x3, double y3) {
      return cross(x2 - x1, y2 - y1, x3 - x2, y3 - y2);
    }

    static double ccw(Point2D p1, Point2D p2, Point2D p3) {
      return ccw(p1.getX(), p1.getY(), p2.getX(), p2.getY(), p3.getX(), p3.getY());
    }

    static double abs(double x, double y) {
      return Math.sqrt(x * x + y * y);
    }
  }

  /**
   * http://qiita.com/p_shiki37/items/65c18f88f4d24b2c528b
   */
  static class FastScanner {
    private final InputStream in;
    private final byte[] buffer = new byte[1024];
    private int ptr = 0;
    private int buflen = 0;

    public FastScanner(InputStream in) {
      this.in = in;
    }

    private static boolean isPrintableChar(int c) {
      return 33 <= c && c <= 126;
    }

    private boolean hasNextByte() {
      if (ptr < buflen) {
        return true;
      } else {
        ptr = 0;
        try {
          buflen = in.read(buffer);
        } catch (IOException e) {
          e.printStackTrace();
        }
        if (buflen <= 0) {
          return false;
        }
      }
      return true;
    }

    private int readByte() {
      if (hasNextByte()) return buffer[ptr++];
      else return -1;
    }

    private void skipUnprintable() {
      while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++;
    }

    public boolean hasNext() {
      skipUnprintable();
      return hasNextByte();
    }

    public String next() {
      if (!hasNext()) throw new NoSuchElementException();
      StringBuilder sb = new StringBuilder();
      int b = readByte();
      while (isPrintableChar(b)) {
        sb.appendCodePoint(b);
        b = readByte();
      }
      return sb.toString();
    }

    public long nextLong() {
      if (!hasNext()) throw new NoSuchElementException();
      long n = 0;
      boolean minus = false;
      int b = readByte();
      if (b == '-') {
        minus = true;
        b = readByte();
      }
      if (b < '0' || '9' < b) {
        throw new NumberFormatException();
      }
      while (true) {
        if ('0' <= b && b <= '9') {
          n *= 10;
          n += b - '0';
        } else if (b == -1 || !isPrintableChar(b)) {
          return minus ? -n : n;
        } else {
          throw new NumberFormatException();
        }
        b = readByte();
      }
    }
  }

  static class Pair<F extends Comparable<F>, S extends Comparable<S>> implements Comparable<Pair<F, S>> {
    F f;
    S s;

    Pair() {
    }

    Pair(F f, S s) {
      this.f = f;
      this.s = s;
    }

    Pair(Pair<F, S> p) {
      f = p.f;
      s = p.s;
    }

    @Override
    public int compareTo(Pair<F, S> p) {
      if (f.compareTo(p.f) != 0) {
        return f.compareTo(p.f);
      }
      return s.compareTo(p.s);
    }

    @Override
    public int hashCode() {
      return f.hashCode() ^ s.hashCode();
    }

    @Override
    public boolean equals(Object o) {
      if (this == o) {
        return true;
      }
      if (o == null || this.f == null || this.s == null) {
        return false;
      }
      if (this.getClass() != o.getClass()) {
        return false;
      }
      Pair p = (Pair) o;
      return this.f.equals(p.f) && this.s.equals(p.s);
    }

    @Override
    public String toString() {
      return "{" + f.toString() + ", " + s.toString() + "}";
    }
  }

  class BIT<T> {
    int n;
    ArrayList<T> bit;
    BiFunction<T, T, T> bif;

    /**
     * 1-indexed ???Binary Indexed Tree????§??????????
     *
     * @param n   ??????
     * @param bif ?????¨???????????¢??°
     * @param sup ?????????
     */
    BIT(int n, BiFunction<T, T, T> bif, Supplier<T> sup) {
      this.n = n;
      bit = new ArrayList<>(n + 1);
      for (int i = 0; i < n + 1; ++i) {
        bit.add(sup.get());
      }
      this.bif = bif;
    }

    /**
     * i??????????????????v??§??´??°??????
     *
     * @param i index
     * @param v ??°?????????
     */
    void set(int i, T v) {
      for (int x = i; x <= n; x += x & -x) {
        bit.set(x, bif.apply(bit.get(x), v));
      }
    }

    /**
     * ?????¨??????
     *
     * @param defaultValue ?????????
     * @param i            index
     * @return [1, i]?????§f????????¨????????????
     */
    T reduce(T defaultValue, int i) {
      T ret = defaultValue;
      for (int x = i; x > 0; x -= x & -x) {
        ret = bif.apply(ret, bit.get(x));
      }
      return ret;
    }
  }

  class SegmentTree<T> {
    int n;
    ArrayList<T> dat;
    BiFunction<T, T, T> bif;
    Supplier<T> sup;

    /**
     * 0-indexed ???Segment Tree????§??????????
     *
     * @param n_  ????±???????
     * @param bif ?????¨???????????¢??°
     * @param sup ?????????
     */
    SegmentTree(int n_, BiFunction<T, T, T> bif, Supplier<T> sup) {
      n = 1;
      while (n < n_) n *= 2;

      dat = new ArrayList<>(2 * n - 1);
      for (int i = 0; i < 2 * n - 1; ++i) {
        dat.add(sup.get());
      }
      this.bif = bif;
      this.sup = sup;
    }

    /**
     * k??????????????????v??§??´??°??????
     *
     * @param k index
     * @param v ??°?????????
     */
    void set(int k, T v) {
      k += n - 1;
      dat.set(k, v);
      while (k > 0) {
        k = (k - 1) / 2;
        dat.set(k, bif.apply(dat.get(k * 2 + 1), dat.get(k * 2 + 2)));
      }
    }

    /**
     * ?????¨??????
     *
     * @param l ?????????
     * @param r ?????????
     * @return [l, r)??§?????????bif????????¨?????????????????????
     */
    T reduce(int l, int r) {
      return _reduce(l, r, 0, 0, n);
    }

    T _reduce(int a, int b, int k, int l, int r) {
      if (r <= a || b <= l) return sup.get();
      if (a <= l && r <= b) return dat.get(k);
      T vl = _reduce(a, b, k * 2 + 1, l, (l + r) / 2);
      T vr = _reduce(a, b, k * 2 + 2, (l + r) / 2, r);
      return bif.apply(vl, vr);
    }
  }

  class UnionFind {
    int[] par;

    UnionFind(int n) {
      par = new int[n];
      for (int i = 0; i < n; ++i) {
        par[i] = i;
      }
    }

    int find(int x) {
      if (par[x] == x) {
        return x;
      }
      return par[x] = find(x);
    }

    boolean same(int x, int y) {
      return find(x) == find(y);
    }

    void union(int x, int y) {
      x = find(x);
      y = find(y);
      if (x == y) {
        return;
      }
      par[x] = y;
    }
  }
}