// - Art -
#include <bits/stdc++.h>
#define el cout << '\n'
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define REV(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define REP(i, c) for (int i = 0, _c = (c); i < _c; ++i)
const int N = 2e5 + 7;
const int BLOCKSIZE = 320;
const int MOD = 1e9 + 7;
using namespace std;
int x[N], d[N];
int dp[N], f[N][BLOCKSIZE + 7];
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int n;
cin >> n;
FOR (i, 1, n) {
cin >> d[i] >> x[i];
dp[i] = 1;
}
REV (i, n, 1) {
if (d[i] > BLOCKSIZE) {
for (int j = i + d[i]; j <= min(1LL * n, i + 1LL * x[i] * d[i]); j += d[i]) {
dp[i] = (dp[i] + dp[j]) % MOD;
}
}
else {
if (i + d[i] <= n) {
dp[i] = (1LL * dp[i] + f[i + d[i]][d[i]] - f[min(i + 1LL * (x[i] + 1) * d[i], 1LL * n + 1)][d[i]] + MOD) % MOD;
}
}
FOR (j, 1, BLOCKSIZE) {
int add = 0;
if (i + j <= n) {
add = f[i + j][j];
}
f[i][j] = (dp[i] + add) % MOD;
}
}
cout << dp[1], el;
return 0;
}
