#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC optimize("Ofast")
#define ll long long
#define pii pair<int,int>
#define piii pair<pii,int>
#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define endl "\n"
#define all(a) a.begin(),a.end()
//#define int long long
const int mod=1e9+7;
void solve(){
int n,ans=0;
cin>>n;
int d[n],x[n];
vector<pii> idx[n];
map<pii,vector<int>> mp;
for(int i=0;i<n;++i) cin>>d[i]>>x[i];
for(int i=0;i<n;++i){
int tmp=0;
for(auto[m,r]:idx[i]){
int id=i/m;
auto &it=mp[{m,r}];
if(id) (it[id]+=it[id-1])%=mod;
(tmp+=it[id])%=mod;
}
if(!i) tmp=1;
(ans+=tmp)%=mod;
if(i+d[i]>=n||d[i]==0||x[i]==0) continue;
int k=i%d[i];
auto &it=mp[{d[i],k}];
if(it.empty()){
for(int j=k;j<n;j+=d[i]){
it.pb(0);
idx[j].eb(d[i],k);
}
}
int id=i/d[i];
(it[id+1]+=tmp)%=mod;
if(id+x[i]+1<it.size()){
it[id+x[i]+1]-=tmp;
if(it[id+x[i]+1]<0) it[id+x[i]+1]+=mod;
}
}
cout<<ans;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int t=1;
//cin>>t;
while(t--){
solve();
}
return 0;
}
