#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N = 1e5 + 10, mod = 1e9 + 7, D = 100;
ll n, dp[N], sm[D][D], a[N][2];
vector<ll> del[N];
void add(ll &x, ll y){
x += y;
if (x < 0) x += mod;
if (x >= mod) x -= mod;
}
int main(){
cin >> n;
for (ll i = 1; i <= n; i ++)
cin >> a[i][0] >> a[i][1];
dp[1] = 1;
for (ll i = 1; i <= n; i ++){
for (ll d = 1; d < D; d ++)
add(dp[i], sm[d][i % d]);
for (ll l : del[i]){
// cout << "At " << i << " deleting " << l << " which is " << -dp[l] << " and contents " << a[l][0] << ", " << l % a[l][0] << endl;
add(sm[a[l][0]][l % a[l][0]], -dp[l]);
}
if (!a[i][0] or !a[i][1]) continue;
if (a[i][0] >= D){
for (ll j = i + a[i][0]; j <= n and a[i][1]; j += a[i][0], a[i][1]--)
add(dp[j], dp[i]);
}
else{
add(sm[a[i][0]][i % a[i][0]], dp[i]);
ll r = 1ll * i + 1ll * a[i][0] * a[i][1];
// cout << "Adding " << dp[i] << " on " << a[i][0] << ", " << i % a[i][0] << endl;
if (r <= n)
del[r].push_back(i);
}
}
ll ans = 0;
for (ll i = 1; i <= n; i ++){
// cout << i << " : " << dp[i] << endl;
add(ans, dp[i]);
}
ans %= mod;
ans += mod;
ans %= mod;
cout << ans << endl;
}
