Relic Discovery

Problem Description

Recently, paleoanthropologists have found historical remains on an island in the Atlantic Ocean. The most inspiring thing is that they excavated in a magnificent cave and found that it was a huge tomb. Inside the construction,researchers identified a large number of skeletons, and funeral objects including stone axe, livestock bones and murals. Now, all items have been sorted, and they can be divided into N types. After they were checked attentively, you are told that there are $A_i$ items of the i-th type. Further more, each item of the i-th type requires $B_i$ million dollars for transportation, analysis, and preservation averagely. As your job, you need to calculate the total expenditure.

 

Input

The first line of input contains an integer T which is the number of test cases. For each test case, the first line contains an integer N which is the number of types. In the next N lines, the i-th line contains two numbers $A_i$ and $B_i$ as described above. All numbers are positive integers and less than 101.

 

Output

For each case, output one integer, the total expenditure in million dollars.

 

Sample Input

121 23 4

 

Sample Output

14

 

#include<iostream>#include<cstdio>using namespace std;int main(){    int t;    scanf("%d",&t);    while(t --)    {        int n;        scanf("%d",&n);        long long sum=0;        while(n --)        {            int a,b;            scanf("%d %d",&a,&b);            sum=sum+a*b;        }        printf("%lld\n",sum);    }    return 0;}