#include <bits/stdc++.h>
using namespace std;
int n , a , b , c , s , j , ans;
int main()
{
    cin >> n;
    for ( int i = 1; i <= n; i++ )
    {
        cin >> a >> b >> c;
        s = a + b + c;
        if (j < s )
        {
        	ans++;
		}
        j = s;   
	} 
	cout << ans - 1;
	return 0;
}