description: Little Johnny Bubbles enjoys spending hours in front of his computer playing video games. His favorite game is Bubble Strike, fast-paced bubble shooting online game for two players.
  
  Each game is set in one of the N maps, each having different terrain configuration. First phase of each game decides on which map the game will be played. The game system randomly selects three maps and shows them to the players. Each player must pick one of those three maps to be discarded. The game system then randomly selects one of the maps that were not picked by any of the players and starts the game.
  
  Johnny is deeply enthusiastic about the game and wants to spend some time studying maps, thus increasing chances to win games played on those maps. However, he also needs to do his homework, so he does not have time to study all the maps. That is why he asked himself the following question: "What is the minimum number of maps I have to study, so that the probability to play one of those maps is at least P"?
  
  Can you help Johnny find the answer for this question? You can assume Johnny's opponents do not know him, and they will randomly pick maps.
  
  Input
  
  The first line contains two integers N (3 ≤ N ≤ 10^{3}) and P (0 ≤ P ≤ 1) – total number of maps in the game and probability to play map Johnny has studied. P will have at most four digits after the decimal point.
  
  Output
  
  Output contains one integer number – minimum number of maps Johnny has to study.
  
  Example
  
  Input
  
  
  7 1.0000
  
  
  Output
  
  
  6
solution: 
  import java.io.*;
  import java.util.*;
  
  public final class Main {
  
      static PrintWriter out = new PrintWriter(System.out);
      static FastReader in = new FastReader();
      static Pair[] moves = new Pair[]{new Pair(-1, 0), new Pair(0, 1), new Pair(1, 0), new Pair(0, -1)};
      static int mod = (int) (1e9 + 7);
      static int mod2 = 998244353;
  
      public static void main(String[] args) {
          int tt = 1;
          while (tt-- > 0) {
              solve();
          }
          out.flush();
      }
  
      public static void solve() {
          int n = i();
          double p = d();
  
          int l = 0;
          int r = n - 1;
          while (l < r) {
              int m = (l + r) / 2;
              double x = cal(m, n);
              if (x >= p) {
                  r = m;
              } else {
                  l = m + 1;
              }
          }
          out.println(l);
      }
  
      private static double cal(int m, int n) {
          long ttl = comb(n, 3);
          double ans = 0d;
          ans += 1d * (comb(m, 3));
          ans += 1d * (comb(m, 2) * comb(n - m, 1));
          ans += 0.5 * (comb(m, 1) * comb(n - m, 2));
          return ans / ttl;
      }
  
      private static long comb(int n, int c) {
          if (c > n) {
              return 0;
          }
          if (c == n) {
              return 1;
          }
          long ans = 1L;
          for (int i = 0; i < c; i++) {
              ans *= (n - i);
          }
          for (int i = 1; i <= c; i++) {
              ans /= i;
          }
          return ans;
      }
  
      static long[] pre(int[] a) {
          long[] pre = new long[a.length + 1];
          pre[0] = 0;
          for (int i = 0; i < a.length; i++) {
              pre[i + 1] = pre[i] + a[i];
          }
          return pre;
      }
  
      static void print(char A[]) {
          for (char c : A) {
              out.print(c);
          }
          out.println();
      }
  
      static void print(boolean A[]) {
          for (boolean c : A) {
              out.print(c + " ");
          }
          out.println();
      }
  
      static void print(int A[]) {
          for (int c : A) {
              out.print(c + " ");
          }
          out.println();
      }
  
      static void print(long A[]) {
          for (long i : A) {
              out.print(i + " ");
          }
          out.println();
      }
  
      static void print(List<Integer> A) {
          for (int a : A) {
              out.print(a + " ");
          }
      }
  
      static int i() {
          return in.nextInt();
      }
  
      static long l() {
          return in.nextLong();
      }
  
      static double d() {
          return in.nextDouble();
      }
  
      static String s() {
          return in.nextLine();
      }
  
      static int[][] inputWithIdx(int N) {
          int A[][] = new int[N][2];
          for (int i = 0; i < N; i++) {
              A[i] = new int[]{i, in.nextInt()};
          }
          return A;
      }
  
      static int[] input(int N) {
          int A[] = new int[N];
          for (int i = 0; i < N; i++) {
              A[i] = in.nextInt();
          }
          return A;
      }
  
      static long[] inputLong(int N) {
          long A[] = new long[N];
          for (int i = 0; i < A.length; i++) {
              A[i] = in.nextLong();
          }
          return A;
      }
  
      static int GCD(int a, int b) {
          if (b == 0) {
              return a;
          } else {
              return GCD(b, a % b);
          }
      }
  
      static long GCD(long a, long b) {
          if (b == 0) {
              return a;
          } else {
              return GCD(b, a % b);
          }
      }
  
      static long LCM(int a, int b) {
          return (long) a / GCD(a, b) * b;
      }
  
      static long LCM(long a, long b) {
          return a / GCD(a, b) * b;
      }
  
      static void shuffleAndSort(int[] arr) {
          for (int i = 0; i < arr.length; i++) {
              int rand = (int) (Math.random() * arr.length);
              int temp = arr[rand];
              arr[rand] = arr[i];
              arr[i] = temp;
          }
          Arrays.sort(arr);
      }
  
      static void shuffleAndSort(int[][] arr, Comparator<? super int[]> comparator) {
          for (int i = 0; i < arr.length; i++) {
              int rand = (int) (Math.random() * arr.length);
              int[] temp = arr[rand];
              arr[rand] = arr[i];
              arr[i] = temp;
          }
          Arrays.sort(arr, comparator);
      }
  
      static void shuffleAndSort(long[] arr) {
          for (int i = 0; i < arr.length; i++) {
              int rand = (int) (Math.random() * arr.length);
              long temp = arr[rand];
              arr[rand] = arr[i];
              arr[i] = temp;
          }
          Arrays.sort(arr);
      }
  
      static boolean isPerfectSquare(double number) {
          double sqrt = Math.sqrt(number);
          return ((sqrt - Math.floor(sqrt)) == 0);
      }
  
      static void swap(int A[], int a, int b) {
          int t = A[a];
          A[a] = A[b];
          A[b] = t;
      }
  
      static long pow(long a, long b, int mod) {
          long pow = 1;
          long x = a;
          while (b != 0) {
              if ((b & 1) != 0) {
                  pow = (pow * x) % mod;
              }
              x = (x * x) % mod;
              b /= 2;
          }
          return pow;
      }
  
      static long pow(long a, long b) {
          long pow = 1;
          long x = a;
          while (b != 0) {
              if ((b & 1) != 0) {
                  pow *= x;
              }
              x = x * x;
              b /= 2;
          }
          return pow;
      }
  
      static long modInverse(long x, int mod) {
          return pow(x, mod - 2, mod);
      }
  
      static boolean isPrime(long N) {
          if (N <= 1) {
              return false;
          }
          if (N <= 3) {
              return true;
          }
          if (N % 2 == 0 || N % 3 == 0) {
              return false;
          }
          for (int i = 5; i * i <= N; i = i + 6) {
              if (N % i == 0 || N % (i + 2) == 0) {
                  return false;
              }
          }
          return true;
      }
  
      public static String reverse(String str) {
          if (str == null) {
              return null;
          }
          return new StringBuilder(str).reverse().toString();
      }
  
      public static String repeat(char ch, int repeat) {
          if (repeat <= 0) {
              return "";
          }
          final char[] buf = new char[repeat];
          for (int i = repeat - 1; i >= 0; i--) {
              buf[i] = ch;
          }
          return new String(buf);
      }
  
      public static int[] manacher(String s) {
          char[] chars = s.toCharArray();
          int n = s.length();
          int[] d1 = new int[n];
          for (int i = 0, l = 0, r = -1; i < n; i++) {
              int k = (i > r) ? 1 : Math.min(d1[l + r - i], r - i + 1);
              while (0 <= i - k && i + k < n && chars[i - k] == chars[i + k]) {
                  k++;
              }
              d1[i] = k--;
              if (i + k > r) {
                  l = i - k;
                  r = i + k;
              }
          }
          return d1;
      }
  
      public static int[] kmp(String s) {
          int n = s.length();
          int[] res = new int[n];
          for (int i = 1; i < n; ++i) {
              int j = res[i - 1];
              while (j > 0 && s.charAt(i) != s.charAt(j)) {
                  j = res[j - 1];
              }
              if (s.charAt(i) == s.charAt(j)) {
                  ++j;
              }
              res[i] = j;
          }
          return res;
      }
  }
  
  class Pair {
  
      int i, j;
  
      Pair(int i, int j) {
          this.i = i;
          this.j = j;
      }
  
      @Override
      public boolean equals(Object o) {
          if (this == o) {
              return true;
          }
          if (o == null || getClass() != o.getClass()) {
              return false;
          }
          Pair pair = (Pair) o;
          return i == pair.i && j == pair.j;
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(i, j);
      }
  }
  
  class FastReader {
  
      BufferedReader br;
      StringTokenizer st;
  
      public FastReader() {
          br = new BufferedReader(new InputStreamReader(System.in));
      }
  
      String next() {
          while (st == null || !st.hasMoreElements()) {
              try {
                  st = new StringTokenizer(br.readLine());
              } catch (IOException e) {
                  e.printStackTrace();
              }
          }
          return st.nextToken();
      }
  
      int nextInt() {
          return Integer.parseInt(next());
      }
  
      long nextLong() {
          return Long.parseLong(next());
      }
  
      double nextDouble() {
          return Double.parseDouble(next());
      }
  
      String nextLine() {
          String str = "";
          try {
              str = br.readLine();
          } catch (IOException e) {
              e.printStackTrace();
          }
          return str;
      }
  }
  
  class Node {
  
      int data, open, close;
  
      Node() {
          this(0, 0, 0);
      }
  
      Node(int data, int open, int close) {
          this.data = data;
          this.open = open;
          this.close = close;
      }
  }
  
  class ST {
  
      int n;
      Node[] st;
  
      ST(int n) {
          this.n = n;
          st = new Node[4 * Integer.highestOneBit(n)];
      }
  
      void build(Node[] nodes) {
          build(0, 0, n - 1, nodes);
      }
  
      private void build(int id, int l, int r, Node[] nodes) {
          if (l == r) {
              st[id] = nodes[l];
              return;
          }
          int mid = (l + r) >> 1;
          build((id << 1) + 1, l, mid, nodes);
          build((id << 1) + 2, mid + 1, r, nodes);
          st[id] = comb(st[(id << 1) + 1], st[(id << 1) + 2]);
      }
  
      void update(int i, Node node) {
          update(0, 0, n - 1, i, node);
      }
  
      private void update(int id, int l, int r, int i, Node node) {
          if (i < l || r < i) {
              return;
          }
          if (l == r) {
              st[id] = node;
              return;
          }
          int mid = (l + r) >> 1;
          update((id << 1) + 1, l, mid, i, node);
          update((id << 1) + 2, mid + 1, r, i, node);
          st[id] = comb(st[(id << 1) + 1], st[(id << 1) + 2]);
      }
  
      Node get(int x, int y) {
          return get(0, 0, n - 1, x, y);
      }
  
      private Node get(int id, int l, int r, int x, int y) {
          if (x > r || y < l) {
              return new Node();
          }
          if (x <= l && r <= y) {
              return st[id];
          }
          int mid = (l + r) >> 1;
          return comb(get((id << 1) + 1, l, mid, x, y), get((id << 1) + 2, mid + 1, r, x, y));
      }
  
      Node comb(Node a, Node b) {
          if (a == null) {
              return b;
          }
          if (b == null) {
              return a;
          }
          int min = Math.min(a.open, b.close);
          return new Node(a.data + b.data + min * 2, a.open + b.open - min, a.close + b.close - min);
      }
  }