#include<iostream> #include<cstring> using namespace std; int isPrime[1001]; bool func(int num){     for (int i = 2; i < num; i++){         if (num%i == 0) isPrime[num] = 0;     }     if (isPrime[num] == -1) {         isPrime[num] = 1;         return true;     }     for (int i = 2; i < num; i++){         if (isPrime[i] == 1){             int buf = i;             while (buf <= num){                 if (buf == num) return true;                 buf *= i;             }         }     }     return false; } int main(){     int n;     cin >> n;     int res = 0;     memset(isPrime, -1, 1001);     for (int i = 2; i <= n; i++){         if (func(i)) res++;     }     cout << res;     return 0; }