#include <iostream>
using namespace std;


const int INF = 0x70123456;
const int MAX_N = 105;

int need[MAX_N], price[MAX_N];

int dp[MAX_N];

int _min(int a, int b);

int main()
{
	int T, c;

	scanf("%d", &T);

	while (T--)
	{
		scanf("%d", &c);

		for (int i = 1; i <= c; i++)
		{
			scanf("%d%d", need + i, price + i);
			dp[i] = INF;
		}
		
		for (int i = 1; i <= c; i++)
		{
			int s = 10;
			for (int j = i; j; j--)
			{
				s += need[j];
				dp[i] = _min(dp[i], dp[j - 1] + s * price[i]);
			}
		}

		printf("%d\n", dp[c]);
	}
	return 0;
}

int _min(int a, int b)
{
	return a < b ? a : b;
}