#include <bits/stdc++.h>
using namespace std;
const int N = 1e5+10, S_N = 317, mod = 1e9+7;
int d[N], x[N];
int dp[N];
int qs[S_N][2*N];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n;
cin >> n;
for(int i = 1; i <= n; ++i){
cin >> d[i] >> x[i];
d[i] = min(d[i], n);
x[i] = min(x[i], n);
}
for(int i = n; i >= 1; --i){
dp[i] = 1;
if(d[i] != 0) if(d[i] < S_N){
int hi = min(1LL*n+d[i], i + 1LL*(x[i]+1)*d[i]);
while(hi % d[i] != i % d[i]) hi--;
int lo = min(n, i + d[i]);
while(lo % d[i] != i % d[i]) lo--;
dp[i] += (1LL*qs[d[i]][lo] - qs[d[i]][hi])%mod;
}else{
for(int j = 1, cur = i+d[i]; j <= x[i] && cur < n; ++j, cur += d[i]) dp[i] = (dp[i] + dp[cur])%mod;
}
for(int j = 1; j < S_N; ++j) qs[j][i] = (1LL*dp[i] + (i+j > n ? 0 : qs[j][i+j]))%mod;
}
cout << dp[1] << '\n';
}
