#include<bits/stdc++.h> using namespace std; using ll = long long; void solve() { int n; cin>>n; int ct=0; for(int i=0; i<n; ++i) { int x,y; cin>>x>>y; if(x>y) ct++; } cout<<ct<<endl; } int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int TC = 1; cin >> TC; cin.ignore(); while (TC--) solve(); }