#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int mod = 1e9+7, N = 1e5, S = 317;
ll dp[N];
int main() {
int n;
cin >> n;
vector<int> d(n), x(n);
for (int i = 0; i < n; ++i) cin >> d[i] >> x[i];
vector<int> final(n);
for (int i = 0; i < n; ++i) final[i] = min(n, i+d[i]*(x[i]+1));
dp[n-1] = 1;
vector<vector<ll>> suff(S, vector<ll>(n+1, 0));
for (int i = n-1; i >= 0; --i) {
dp[i] = 1;
if (d[i] >= S) {
for (int j = i+d[i]; j <= i+d[i]*x[i]; j+=d[i]) {
dp[i] += dp[j];
dp[i] %= mod;
}
} else if (d[i] > 0) {
dp[i] = (suff[d[i]][i+d[i]]-suff[d[i]][final[i]]+mod)%mod;
}
for (int j = 1; j < S; ++j) suff[j][i] = (suff[j][min(n, i+j)]+dp[i])%mod;
}
cout << dp[0] << endl;
return 0;
}
