The clique problem is one of the most well-known NP-complete problems. Under some simplification it can be formulated as follows. Consider an undirected graph G. It is required to find a subset of vertices C of the maximum size such that any two of them are connected by an edge in graph G. Sounds simple, doesn't it? Nobody yet knows an algorithm that finds a solution to this problem in polynomial time of the size of the graph. However, as with many other NP-complete problems, the clique problem is easier if you consider a specific type of a graph.

Consider n distinct points on a line. Let the i-th point have the coordinate xi and weight wi. Let's form graph G, whose vertices are these points and edges connect exactly the pairs of points (i, j), such that the distance between them is not less than the sum of their weights, or more formally: |xi - xj| ≥ wi + wj.

Find the size of the maximum clique in such graph.

Input

The first line contains the integer n (1 ≤ n ≤ 200 000) — the number of points.

Each of the next n lines contains two numbers xi, wi (0 ≤ xi ≤ 109, 1 ≤ wi ≤ 109) — the coordinate and the weight of a point. All xi are different.

Output

Print a single number — the number of vertexes in the maximum clique of the given graph.

Examples

Input

4
2 3
3 1
6 1
0 2


Output

3

Note

If you happen to know how to solve this problem without using the specific properties of the graph formulated in the problem statement, then you are able to get a prize of one million dollars!

The picture for the sample test.

<image>
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Arrays;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.io.Closeable;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) throws Exception {
        Thread thread = new Thread(null, new TaskAdapter(), "", 1 << 29);
        thread.start();
        thread.join();
    }

    static class TaskAdapter implements Runnable {
        @Override
        public void run() {
            InputStream inputStream = System.in;
            OutputStream outputStream = System.out;
            FastInput in = new FastInput(inputStream);
            FastOutput out = new FastOutput(outputStream);
            BCliqueProblem solver = new BCliqueProblem();
            solver.solve(1, in, out);
            out.close();
        }
    }

    static class BCliqueProblem {
        public void solve(int testNumber, FastInput in, FastOutput out) {
            int n = in.ri();
            MaximumNotIntersectIntervals.Interval[] intervals = new MaximumNotIntersectIntervals.Interval[n];
            for (int i = 0; i < n; i++) {
                int x = in.ri();
                int w = in.ri();
                intervals[i] = new MaximumNotIntersectIntervals.Interval(x - w, x + w);
            }
            long ans = new MaximumNotIntersectIntervals(intervals).query(-(long) 1e18, (long) 1e18);
            out.println(ans);
        }

    }

    static class FastOutput implements AutoCloseable, Closeable, Appendable {
        private static final int THRESHOLD = 1 << 13;
        private final Writer os;
        private StringBuilder cache = new StringBuilder(THRESHOLD * 2);

        public FastOutput append(CharSequence csq) {
            cache.append(csq);
            return this;
        }

        public FastOutput append(CharSequence csq, int start, int end) {
            cache.append(csq, start, end);
            return this;
        }

        private void afterWrite() {
            if (cache.length() < THRESHOLD) {
                return;
            }
            flush();
        }

        public FastOutput(Writer os) {
            this.os = os;
        }

        public FastOutput(OutputStream os) {
            this(new OutputStreamWriter(os));
        }

        public FastOutput append(char c) {
            cache.append(c);
            afterWrite();
            return this;
        }

        public FastOutput append(long c) {
            cache.append(c);
            afterWrite();
            return this;
        }

        public FastOutput append(String c) {
            cache.append(c);
            afterWrite();
            return this;
        }

        public FastOutput println(long c) {
            return append(c).println();
        }

        public FastOutput println() {
            return append(System.lineSeparator());
        }

        public FastOutput flush() {
            try {
                os.append(cache);
                os.flush();
                cache.setLength(0);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
            return this;
        }

        public void close() {
            flush();
            try {
                os.close();
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        public String toString() {
            return cache.toString();
        }

    }

    static class Log2 {
        public static int floorLog(int x) {
            if (x <= 0) {
                throw new IllegalArgumentException();
            }
            return 31 - Integer.numberOfLeadingZeros(x);
        }

    }

    static class FastInput {
        private final InputStream is;
        private byte[] buf = new byte[1 << 13];
        private int bufLen;
        private int bufOffset;
        private int next;

        public FastInput(InputStream is) {
            this.is = is;
        }

        private int read() {
            while (bufLen == bufOffset) {
                bufOffset = 0;
                try {
                    bufLen = is.read(buf);
                } catch (IOException e) {
                    bufLen = -1;
                }
                if (bufLen == -1) {
                    return -1;
                }
            }
            return buf[bufOffset++];
        }

        public void skipBlank() {
            while (next >= 0 && next <= 32) {
                next = read();
            }
        }

        public int ri() {
            return readInt();
        }

        public int readInt() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            int val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

    }

    static class MaximumNotIntersectIntervals {
        MaximumNotIntersectIntervals.Interval[] movies;
        int m;
        int[][] jump;

        public MaximumNotIntersectIntervals(MaximumNotIntersectIntervals.Interval[] movies) {
            this.movies = movies;
            Arrays.sort(movies, (a, b) -> Long.compare(a.l, b.l));
            int wpos = 1;
            for (int i = 1; i < movies.length; i++) {
                while (wpos > 0 && movies[wpos - 1].r >= movies[i].r) {
                    wpos--;
                }
                if (wpos == 0 || movies[wpos - 1].l < movies[i].l) {
                    movies[wpos++] = movies[i];
                }
            }
            m = wpos;

            int log = Log2.floorLog(m);
            jump = new int[log + 1][m];
            for (int i = m - 1, r = m; i >= 0; i--) {
                while (r - 1 >= i && movies[r - 1].l >= movies[i].r) {
                    r--;
                }
                jump[0][i] = r;
            }

            for (int i = 0; i + 1 <= log; i++) {
                for (int j = 0; j < m; j++) {
                    jump[i + 1][j] = jump[i][j] == m ?
                            m : jump[i][jump[i][j]];
                }
            }
        }

        public int query(long l, long r) {
            if (m == 0) {
                return 0;
            }
            int lo = 0;
            int hi = m - 1;
            while (lo < hi) {
                int mid = (lo + hi) >> 1;
                if (movies[mid].l < l) {
                    lo = mid + 1;
                } else {
                    hi = mid;
                }
            }
            if (movies[lo].l < l || movies[lo].r > r) {
                return 0;
            }
            int start = lo;
            int ans = 1;
            for (int i = jump.length - 1; i >= 0; i--) {
                if (jump[i][start] == m || movies[jump[i][start]].r > r) {
                    continue;
                }
                ans += 1 << i;
                start = jump[i][start];
            }
            return ans;
        }

        public String toString() {
            return Arrays.toString(Arrays.copyOf(movies, m));
        }

        public static class Interval {
            public long l;
            public long r;

            public Interval(long l, long r) {
                this.l = l;
                this.r = r;
            }

            public String toString() {
                return String.format("[%d, %d]", l, r);
            }

        }

    }
}

