#include <bits/stdc++.h>   using namespace std;   long long i, n, m, k, x, z, c, a[500007], b[500007], ans, bad, total;   int main() {     cin >> n;     for (i = 1; i <= n; i++) cin >> a[i];     set<long long> st;     for (i = 1; i <= n; i++) {       st.insert(a[i]);       if (st.find(i) != st.end()) st.erase(i);       if (st.size() == 0) c++;     }     cout << c << endl;     return 0;   }   