#include <bits/stdc++.h>
#define int long long
#define all(a) begin(a), end(a)
using namespace std;

const int N = 2e5 + 11;
int p[N], q[N];
long double r[N], s_r[N];
int s1[N], s2[N];

int pm(int a, int b, int p){
	if (b == 0) return 1;
	return pm(a * a % p, b / 2, p) * (b % 2 ? a : 1) % p;
}

int mi(int a, int p){
	return pm(a, p - 2, p);
}

void calc(int n, int mod, int* s){
	s[0] = 0;
	for (int i = 0; i < n; i++) {
		s[i + 1] = ((s[i] + p[i] * mi(q[i], mod)) % mod + mod) % mod; 
	}
	for (int i = 1; i <= n; i++) {
		s[i] -= (int) roundl(s_r[i]);
		if (s[i] < 0) s[i] += mod;
	}
}

void solve() {
	int n; cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> p[i] >> q[i]; r[i] = (long double) p[i] / q[i], s_r[i + 1] = s_r[i] + r[i];
	}
	calc(n, 1e9 + 7, s1);
	calc(n, 998244353, s2);

	map<pair<int, int>, int> mp;
	int ans = 0;
	for (int i = 0; i <= n; i++) {
		pair<int, int> p = {s1[i], s2[i]};
		ans += mp[p]; mp[p]++;
	}
	cout << ans << '\n';
}

int32_t main(){
#ifndef LOCAL
	cin.tie(0)->sync_with_stdio(false);
#endif
	int t = 1;
	// cin >> t;
	while (t--) {
		solve();
	}
}