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

#define rep(i, n) for( ll i = 0; i < n; i++ )
using ll = long long;

int main() {
	int N;
	cin >> N;
	int ans = 0;
	rep(i, N) {
		int a, b;
		cin >> a >> b;
		if(a > b) continue;
		ans++;
	}
	cout << ans << endl;
}