#include <bits/stdc++.h>
/*
Go from city i to i + k*d_i
Sqrt
*/
int midc=300;
int main(){
std::ios::sync_with_stdio(0);
std::cin.tie(0);
int n;
std::cin>>n;
std::vector<std::vector<int>> mods(1);
std::vector<int> specials(n);
std::vector<std::vector<std::pair<int,int>>> events(n);
for(int i=1;i<=midc;i++){
mods.emplace_back(i+1);
}
int result=0;
for(int i=0;i<n;i++){
int a,b;
std::cin>>a>>b;
int curtot=(i==0);
for(int j=0;j<midc;j++){
curtot+=mods[j+1][i%(j+1)];
curtot%=1000000007;
}
curtot+=specials[i];
curtot%=1000000007;
result+=curtot;
result%=1000000007;
if(a>0){
if(a<=midc){
mods[a][i%a]+=curtot;
mods[a][i%a]%=1000000007;
if(i+(long long)a*b<n)events[i+a*b].push_back({a,(1000000007-curtot)%1000000007});
}else{
for(int j=1;j<=b&&(i+(long long)a*j)<n;j++){
specials[i+a*j]+=curtot;
specials[i+a*j]%=1000000007;
}
}
}
for(std::pair<int,int> j:events[i]){
mods[j.first][i%j.first]+=j.second;
mods[j.first][i%j.first]%=1000000007;
}
}
std::cout<<result<<'\n';
}
