// #pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#include <bits/stdc++.h>
using namespace std;

#define PB emplace_back
#define int long long
#define ll long long
#define vi vector<int>
#define siz(a) ((int) ((a).size()))
#define rep(i, a, b) for (int i = (a); i <= (b); ++i)
#define per(i, a, b) for (int i = (a); i >= (b); --i)
void print(vi n) { rep(i, 0, siz(n) - 1) cerr << n[i] << " \n"[i == siz(n) - 1]; }

const int N = 2e5, mod = 1e9 + 7;
int a, s[N + 5], inv[N + 5];
long double t[N + 5];
map<int, int> mp;

signed main() {
	// freopen(".in", "r", stdin);
	// freopen(".out", "w", stdout);
	ios::sync_with_stdio(0);
	cin.tie(0), cout.tie(0);
	int tmp = 1;
	rep(i, 1, N) (tmp *= i) %= mod;
	inv[0] = inv[1] = 1;
	rep(i, 2, N) inv[i] = (mod - mod / i) * inv[mod % i] % mod;
	rep(i, 1, N) (inv[i] *= tmp) %= mod;
	cin >> a;
	mp[0] = 1;
	int ans = 0, x, y;
	rep(i, 1, a) {
		cin >> x >> y;
		t[i] = t[i - 1] + 1.0 * x / y;
		s[i] = (x * inv[y] + s[i - 1]) % mod;

		x = t[i];

		// cout << (s[i] - x * tmp % mod + mod) % mod << endl;
		rep(j, x - 5, x + 5) if(mp.count((s[i] - j * tmp % mod + mod) % mod))
		ans += mp[(s[i] - j * tmp % mod + mod) % mod];
		++mp[(s[i] - x *  tmp % mod + mod) % mod];
	}
	cout << ans;
	return cerr << endl << 1.0 * clock() / CLOCKS_PER_SEC << endl, 0;
}