Donation_Drive.cpp

#include <bits/stdc++.h>
using namespace std;

int main() {
	// your code goes here
	int T;
	cin>>T;
    while(T--){
        int N, X;
        cin>>N;
        cin>>X;
        
        int Z;
        Z = N - X;
        cout<<Z<<endl;
        
    }
}