CCF 202012-1 期末预测之安全指数

#include <iostream>
//#include <bits/stdc++.h>
#include <string>

using namespace std;

int main()
{
    int number;
    cin>>number;
    int sum=0;
    int a,b;
    while(number--)
    {
        cin>>a>>b;
        sum+=a*b;
    }
    sum=max(sum,0);
    cout<<sum;
}