#include <bits/stdc++.h>
#define pb push_back
#define ll long long int
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
using namespace std;
vector<ll> ans(100005);
int main() {
int n; cin >> n;
queue<pair<int,ll>> st;
ll cur = 0, sum = 0;
for (int i = 1; i <= n; i++) {
ll d, x; cin >> d >> x;
ans[i] = sum; ans[1] = 1; sum %= 1000000007;
if (x > 0) {st.push({i+x, ans[i]}); sum += ans[i];}
while (st.front().fi <= i) {sum -= st.front().se; st.pop();}
cur += ans[i]; cur %= 1000000007;
}
cout << cur;
return 0;
}
