PSR_of

# include <iostream>
using namespace std;


int main()
{
    int N, sol = 0; cin >> N;
    for (int i = 1; i<= N; i++)
    {
        long long a,r ; cin>>a>>r;
        long long r_c = a*a+3*a+1;
        if (r == r_c) sol++;
    }
    cout<<sol;
    return 0;
}