#include<bits/stdc++.h>
using ll = long long;
using namespace std;
#define rep(i,n) for(int i=0;i<(int)n;i++)

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