#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int NMAX = 1e5;
const int LIM = 320;
const int MOD = 1e9 + 7;
void add(int & x, const int & y) {
x += y;
x >= MOD && (x -= MOD);
}
void sub(int & x, const int & y) {
x -= y;
x < 0 && (x += MOD);
}
int n;
int d[NMAX + 1], x[NMAX + 1];
int dp[NMAX + 1];
int sumdp[NMAX + 1][LIM];
void read() {
cin >> n;
for (int i = 1; i <= n; i++) {
cin >> d[i] >> x[i];
}
}
void solve() {
for (int i = n; i >= 1; i--) {
dp[i] = 1;
if (d[i] >= LIM) {
for (int pos = i + d[i], cnt = 1; pos <= n && cnt <= x[i]; pos += d[i], cnt++)
add(dp[i], dp[pos]);
} else if (d[i] != 0) {
int nr = min(x[i], (n - i) / d[i]) + 1;
add(dp[i], sumdp[i + d[i]][d[i]]);
if (i + nr * d[i] <= n) sub(dp[i], sumdp[i + nr * d[i]][d[i]]);
}
for (int m = 1; m < LIM; m++) {
sumdp[i][m] = i + m <= n ? sumdp[i + m][m] : 0;
add(sumdp[i][m], dp[i]);
}
}
cout << dp[1] << '\n';
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
read();
solve();
return 0;
}
