#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = 105;
const int inf = 0x7f;
int a[maxn],p[maxn],r[maxn],dp[maxn];
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n,c,t;
    cin>>n;
    while(n--){
        cin>>c;
        r[0] = 0;
        for(int i=1;i<=c;i++){
            cin>>a[i]>>p[i];
            r[i] = r[i-1]+a[i];
        }
        memset(dp,inf,sizeof(dp));
        dp[0] = 0;
        for(int i=1;i<=c;i++){
            for(int j=0;j<i;j++){
                dp[i] = min(dp[i],dp[j]+(r[i]-r[j]+10)*p[i]);
            }
        }
        cout<<dp[c]<<endl;
    }
    return 0;
}