http://118.190.20.162/view.page?gpid=T123
9分钟 100分
#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
using namespace std;
int main(){
int n;
scanf("%d", &n);
long long sum = 0;
int w, score;
while(n--){
scanf("%d%d", &w, &score);
sum += w * score;
}
if(sum > 0){
cout << sum << endl;
}else{
cout << 0 << endl;
}
return 0;
}