// Pratiyush Mishra #include <bits/stdc++.h> #define ll long long int using namespace std; void mainSolve() { int x, y; cin >> x >> y; int ans = x - y; cout << ans << endl; } int main() { #ifndef ONLINE_JUDGE freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); #endif int t; cin >> t; while (t--) { mainSolve(); } return 0; }