Ivan recently bought a detective book. The book is so interesting that each page of this book introduces some sort of a mystery, which will be explained later. The i-th page contains some mystery that will be explained on page a_i (a_i ≥ i).

Ivan wants to read the whole book. Each day, he reads the first page he didn't read earlier, and continues to read the following pages one by one, until all the mysteries he read about are explained and clear to him (Ivan stops if there does not exist any page i such that Ivan already has read it, but hasn't read page a_i). After that, he closes the book and continues to read it on the following day from the next page.

How many days will it take to read the whole book?

Input

The first line contains single integer n (1 ≤ n ≤ 10^4) — the number of pages in the book.

The second line contains n integers a_1, a_2, ..., a_n (i ≤ a_i ≤ n), where a_i is the number of page which contains the explanation of the mystery on page i.

Output

Print one integer — the number of days it will take to read the whole book.

Example

Input


9
1 3 3 6 7 6 8 8 9


Output


4

Note

Explanation of the example test:

During the first day Ivan will read only the first page. During the second day Ivan will read pages number 2 and 3. During the third day — pages 4-8. During the fourth (and the last) day Ivan will read remaining page number 9.
//package math_codet;

import java.io.*;
import java.util.*;

public class lets_do {
    FastReader in;
    PrintWriter out;
    Helper_class h;
    final long mod = 1000000007;
    final int MAXN = 1000005;
    final int lgN = 20;
    final int INF = (int)1e8;
    public static void main(String[] args) throws java.lang.Exception{
        new lets_do().run();
    }
    void run() throws Exception{
        in=new FastReader(System.in);
        out = new PrintWriter(System.out);
        h = new Helper_class();
        int t = 1;
        while(t--> 0)
            solve();
        out.flush();
        out.close();
    }
    void solve(){
        int n = h.ni();
        int[] arr = new int[n + 1];
        int i = 0;
        for(i = 1; i <= n; i++)
            arr[i] = h.ni();
        boolean[] vis = new boolean[n];
        int cnt =0;
        int last = 1;
        int hola = 0;
        for(i = 1; i <= n; i++) {
        	if(i > hola)
        		cnt++;
        	hola = Math.max(hola,  arr[i]);
        }
        h.pn(cnt);
    }



    final Comparator<Pair> com=new Comparator<Pair>(){
        public int compare(Pair a, Pair b){
            if(Integer.compare(a.y, b.y) != 0)
                return Integer.compare(a.y, b.y);
            else
                return Integer.compare(a.x, b.x);
        }
    };

    class Pair{
        int x;
        int y;
        Pair(int p, int q){
            x = p;
            y = q;
        }
    }
    class Edge{
        int u , v;
        int wt;
        Edge(int a, int b, int w){
            u = a;
            v = b;
            wt = w;
        }
        int other(int x) {
            return u ^ v ^ x;
        }
    }


    class Helper_class{
        long gcd(long a, long b){return (b==0)?a:gcd(b,a%b);}
        int gcd(int a, int b){return (b==0)?a:gcd(b,a%b);}
        int bitcount(long n){return (n==0)?0:(1+bitcount(n&(n-1)));}
        void p(Object o){out.print(o);}
        void pn(Object o){out.println(o);}
        void pni(Object o){out.println(o);out.flush();}
        String n(){return in.next();}
        String nln(){return in.nextLine();}
        int ni(){return Integer.parseInt(in.next());}
        long nl(){return Long.parseLong(in.next());}
        double nd(){return Double.parseDouble(in.next());}

        long mul(long a,long b){
            if(a>=mod)a%=mod;
            if(b>=mod)b%=mod;
            a*=b;
            if(a>=mod)a%=mod;
            return a;
        }
        long modPow(long a, long p){
            long o = 1;
            while(p>0){
                if((p&1)==1)o = mul(o,a);
                a = mul(a,a);
                p>>=1;
            }
            return o;
        }
        long add(long a, long b){
            if(a>=mod)a%=mod;
            if(b>=mod)b%=mod;
            if(b<0)b+=mod;
            a+=b;
            if(a>=mod)a-=mod;
            return a;
        }
    }

    class FastReader{
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1)
                throw new UnknownError();
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new UnknownError();
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }

        public int peek() {
            if (numChars == -1)
                return -1;
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    return -1;
                }
                if (numChars <= 0)
                    return -1;
            }
            return buf[curChar];
        }

        public void skip(int x) {
            while (x-- > 0)
                read();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public String nextString() {
            return next();
        }

        public String next() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuffer res = new StringBuffer();
            do {
                res.appendCodePoint(c);
                c = read();
            } while (!isSpaceChar(c));

            return res.toString();
        }

        public String nextLine() {
            StringBuffer buf = new StringBuffer();
            int c = read();
            while (c != '\n' && c != -1) {
                if (c != '\r')
                    buf.appendCodePoint(c);
                c = read();
            }
            return buf.toString();
        }

        public double nextDouble() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }

        public boolean hasNext() {
            int value;
            while (isSpaceChar(value = peek()) && value != -1)
                read();
            return value != -1;
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
    }
} 