//
// Created by adavy on 8/18/2024.
//
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 1e9 + 7;
int main(){
ll N; cin >> N;
vector<ll> d(N),x(N);
for(int i=0;i<N;++i){
cin >> d[i] >> x[i];
}
vector<ll> dp(N,1);
ll B = floor(sqrt(N))+1;
vector<vector<vector<ll>>> prefs(B); // type, modulo, preflist
for(int i=0;i<B;++i){
prefs[i] = vector<vector<ll>>(B,{0});
}
for(int i=N-1;i>=0;--i){
if (d[i] == 0) {}
else if (d[i] >= B){
for(int j=i+d[i]; j<=min(N-1, i+x[i]*d[i]);j+=d[i]){
dp[i] += dp[j];
dp[i] %= MOD;
}
}
else {
ll psz = prefs[d[i]][i%d[i]].size();
dp[i] += prefs[d[i]][i%d[i]][psz-1] - prefs[d[i]][i%d[i]][max(0LL,psz-x[i]-1)] + MOD;
dp[i] %= MOD;
}
for(int j=1;j<B;++j){
prefs[j][i%j].push_back((prefs[j][i%j].back()+dp[i])%MOD);
}
}
cout << dp[0] << endl;
return 0;
}
