很想搞个PE的图标，可惜找不到

#include <iostream>
#include <vector>
#include <cmath>
using namespace std;

bool isPrime(int num) {
if(num <= 1) return false;
for(int i = 2; i <= sqrt(num); ++i) {
if(num % i == 0) return false;
}
return true;
}

int main() {
int n, m;
cin >> n >> m;
vector<int> cards(n);
vector<int> selected(m);

for(int i = 0; i < n; ++i) {
    cin >> cards[i];
}

for(int i = 0; i < m; ++i) {
    cin >> selected[i];
    selected[i]--; // 转换为0-based索引
}

int sum = 0;
for(int idx : selected) {
    if(isPrime(cards[idx])) {
        sum += cards[idx];
    }
}
cout << sum << endl;
return 0;

}