A

#include <bits/stdc++.h>

using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)
#define pb     push_back
#define ppb    pop_back
#define ppf    pop_front

int main()
{
    _test
    {
        int n;
        cin>>n;

        int ans = 0;

        for(int i=0; i<n; i++)
        {
            int a, b;
            cin>>a>>b;

            ans += (a > b);
        }

        cout<<ans<<"\n";
    }
}