#include<cstdio>
#include<cstring>
#include<algorithm>
#define inf 9999999
using namespace std;
struct kk
{
    int a;
    int p;
    int sum;
}r[200];
int dp[200];
int main()
{
    int t,n,i,j;
    scanf("%d",&t);
    while(t--)
    {
        memset(dp,inf,sizeof(dp));
        scanf("%d",&n);
        r[0].sum=0;
        for(i=1;i<=n;i++)
        {
            scanf("%d%d",&r[i].a,&r[i].p);
            r[i].sum=r[i-1].sum+r[i].a;
        }
        dp[0]=0;
        for(i=1;i<=n;i++)
            for(j=0;j<i;j++)
                dp[i]=min(dp[i],(r[i].sum-r[j].sum+10)*r[i].p+dp[j]);
        printf("%d\n",dp[n]);
    }
    return 0;
}