18 lines
330 B
C++
18 lines
330 B
C++
#include <bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
|
|
bool isPrime(int n) {
|
|
for (int i = 2; i <= n / i; i++)
|
|
if (n % i == 0) return false;
|
|
return true;
|
|
}
|
|
|
|
int main() {
|
|
int n, s = 0;
|
|
cin >> n;
|
|
for (int i = 4; i <= n; i++)
|
|
if (!isPrime(i))s += i;
|
|
cout << s << endl;
|
|
return 0;
|
|
} |