#include<bits/stdc++.h>
#include <chrono>
#include <random>
using namespace std;
#define F first
#define S second
#define pb push_back
#define vll vector<ll>
#define pll pair<ll, ll>
typedef long long ll;
const ll mxN=1e5+5;
const ll A=300;
ll dv[A][A];
ll n;
ll dp[mxN];
ll d[mxN], x[mxN];
vll ot[mxN];
const ll mod=1e9+7;
void solve(){
memset(dp, 0, sizeof(dp));
memset(dv, 0, sizeof(dv));
cin>>n;
for(ll i=0;i<n;i++){
cin>>d[i]>>x[i];
}
ll ans=0;
dp[0]=1;
for(ll i=0;i<n;i++){
for(auto &it:ot[i]){
dv[d[it]][it%d[it]]-=dp[it];
dv[d[it]][it%d[it]]%=mod;
if(dv[d[it]][it%d[it]]<0) dv[d[it]][it%d[it]]+=mod;
}
//cout<<i<<' '<<dp[i]<<'\n';
for(ll j=1;j<A;j++){
dp[i]+=dv[j][i%j];
dp[i]%=mod;
}
ans+=dp[i];
//cout<<i<<' '<<dp[i]<<'\n';
ans%=mod;
if(d[i]==0) continue;
if(d[i]>=A){
for(ll j=1;j<=x[i];j++){
if(i+d[i]*j>=n) break;
dp[i+d[i]*j]+=dp[i];
dp[i+d[i]*j]%=mod;
}
}
else{
dv[d[i]][i%d[i]]+=dp[i];
dv[d[i]][i%d[i]]%=mod;
if(i+d[i]*x[i]+1<n) ot[i+d[i]*x[i]+1].pb(i);
}
}
cout<<ans<<'\n';
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
solve();
return 0;
}
