#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10, S=320, mod=1e9+7;
int d[S][S], f[N];
int a[N], b[N], n;
vector<pair<pair<int, int>, int>> v[N];
void add(int &x, int y){
x=x+y>=mod?x+y-mod:x+y;
}
void sub(int &x, int y){
x=x<y?x-y+mod:x-y;
}
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n;
for (int i=1; i<=n; ++i) cin >> a[i] >> b[i];
f[1]=1;
for (int i=1; i<=n; ++i){
for (int j=1; j<S; ++j) add(f[i], d[j][i%j]);
f[i]%=mod;
for (auto &j:v[i]) sub(d[j.first.first][j.first.second], j.second);
if (!a[i] || !b[i]) continue;
if (a[i]<S){
add(d[a[i]][i%a[i]], f[i]);
if (i+1ll*a[i]*b[i]<=n) v[i+1ll*a[i]*b[i]].push_back({{a[i], i%a[i]}, f[i]});
}else{
for (int j=i+a[i], k=1; j<=n && k<=b[i]; j+=a[i], ++k) add(f[j], f[i]);
}
}
int ans=0;
for (int i=1; i<=n; ++i) add(ans, f[i]);
cout << ans << '\n';
return 0;
}
