#include <bits/stdc++.h> using namespace std; //素数判断 bool sushu(int n){ bool r = true;//假设是素数 int i; for(i = 2;i <= sqrt(n);i++){ if(n % i == 0){ r = false; break; } } if(n <= 1){ r = false; } return r; } //二进制转10进制 int num(char s[]){ int i,r = 0,t = 1; for(i = strlen(s) - 1; i >= 0;i--){ r = r + (s[i] - '0') * t; t = t * 2; } return r; } int main(){ int n,i,c = 0; char s[50]; cin>>n; for(i = 0;i < n;i++){ cin>>s; if(sushu(num(s))){ c++; } } cout<<c<<endl; return 0; } /************************************************************** Problem: 1405 User: admin Language: C++ Result: Accepted Time:18 ms Memory:2072 kb ****************************************************************/