#include <bits/stdc++.h>

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2") 
#define pb push_back
#define F first
#define S second 
#define ld long double
#define all(a) a.begin(),a.end()
#define ll long long
#define pii pair <int,int>
#define sz(v) (int)v.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--)
#define deb(x) cout <<#x << " : " << x << "\n" ;
using namespace std ;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 2e6 + 10, sq = 1e5 , lg = 19,  inf = 1e8+10 , mod = 998244353;
ld p[maxn] ;

signed main(){
    ios_base::sync_with_stdio(false);cin.tie(0);
    int n ;
    cin >> n;
    map <ld,int> mp ;
    ll ans =0 ;
    mp[0]++;
    rep(i , 1, n){
        int a , b;
        cin >> a>> b; 
        p[i] = p[i-1] + (ld)((ld)a/(ld)b) ;
        int z =p[i] ;
        ans += mp[(ld)(p[i]-z)] ;
        mp[(ld)(p[i]-z)] ++ ;
    }
    cout << ans << "\n"; 

    return 0;
}
/*
10 7 4
8 4
9 4
7 2
10 2
4 5
3 5
6 7
*/