#include "bits/stdc++.h"
#define int long long
using namespace std;
const int MOD = 1e9 + 7;
struct fenwick {
int n;
vector<int> b;
fenwick(int n) : n(n), b(n + 1) {}
void update(int i, int x) {
for (; i <= n; i += i & -i)
b[i] = (b[i] + x) % MOD;
}
int query(int i) {
int res = 0;
for (; i >= 1; i -= i & -i)
res = (res + b[i]) % MOD;
return res;
}
int query(int l, int r) {
return (query(r) - query(l - 1) + MOD) % MOD;
}
};
int32_t main() {
ios::sync_with_stdio(0), cin.tie(0);
int n; cin >> n;
vector<pair<int, int>> a(n + 1);
for (int i = 1; i <= n; i++)
cin >> a[i].first >> a[i].second;
fenwick fen(n);
for (int i = 1; i <= n; i++)
fen.update(i, 1);
for (int i = n - 1; i >= 1; i--) {
auto [d, x] = a[i];
if (x == 0) continue;
fen.update(i, fen.query(i + 1, min(i + x, n)));
}
cout << fen.query(1) << '\n';
return 0;
}
