~cpp
#include<iostream>
#include <ctime>
using namespace std;
int main()
{
clock_t t1 = clock();//시간재기위한라인
int i;
int j;
int count;
for(i=2;i<50000;i++){
count=0;
for(j=2;j<i;j++){
if(i%j==0)
{
count++;
break;
}
}
if(count==0)
cout<<i<<"\n";
}
clock_t t = clock() - t1;//시간재기위한라인
cout << (double)(t/CLOCKS_PER_SEC) << "\n";
return 0;
}