hdu2662

Coin

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1130    Accepted Submission(s): 577

Problem Description

Moon has many coins, but only contains two value types which is 5 cents and 7 cents, Some day he find that he can get any value which greater than 23 cents using some of his coins. For instance, he can get 24 cents using two 5 cents coins and two 7 cents coins, he can get 25 cents using five 5 cents coins, he can get 26 cents using one 5 cents coins and three 7 cents coins and so on.

Now, give you many coins which just contains two value types just like Moon, and the two value types identified by two different prime number i and j. Can you caculate the integer n that any value greater than n can be created by some of the given coins.

 

Input

The first line contains an integer T, indicates the number of test cases.
For each test case, there are two different prime i and j separated by a single space.(2<=i<=1000000, 2<=j<=1000000)

 

Output

For each test case, output one line contains the number n adapt the problem description.

 

Sample Input

1 
5 7

 

Sample Output

23

AC代码：
#include <iostream>
#include<algorithm>
#include<cstdio>
#include<cstring>
using namespace std;
typedef unsigned long long int longint;
int main()
{
        int t;
        cin >> t;
        while (t--)
        {
                longint n, m;
                cin >> n >> m;
                longint ans;
                ans = (n * m) - n - m;
                cout << ans << endl;
        }
        return 0;
}