#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define pl pair<long, long>
#define pll pair<ll, ll>
#define f first
#define s second
#define MOD 1000000007
ll ress[100005], ds[100005], xs[100005];
vector<vector<ull> > apsums;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
ll N;
cin >> N;
for (ll i=1; i<1+N; i++) {
cin >> ds[i] >> xs[i];
apsums.push_back(vector<ull>());
apsums[apsums.size()-1].push_back(0);
}
ull xp, res;
for (ll idx=N; idx>0; idx--) {
//cout << "PROCESSING " << idx << endl;
// if no trains
if (ds[idx] == 0) {
res = 1;
ress[idx] = 1;
} else {
xp = min(xs[idx], (N-idx)/ds[idx]);
if (xp == 0) {
ress[idx] = 1;
res = 1;
} else {
/*
res = 1;
// now loop
for (ll p=1; p<=xp; p++) {
res += ress[idx+ds[idx]*p];
res = res%MOD;
}
*/
//cout << "CHECKED IFS" << endl;
// apsums is from the back. if we need 2, length is 5, then we take apsums[idx][4] - apsums[idx][2]
//cout << "XP: " << xp << ", SIZE: " << apsums[idx-1].size() << endl;
//cout << apsums[idx-1][apsums[idx-1].size()-1] << ' ' << apsums[idx-1][apsums[idx-1].size()-1-xp] << endl;
res = 1+(apsums[idx-1][apsums[idx-1].size()-1] + MOD - apsums[idx-1][apsums[idx-1].size()-1-xp])%MOD;
// add to memo
ress[idx] = res;
}
}
//cout << "GOT RES: " << res << endl;
/*cout << "APSUMS: " << endl;
for (int i=0; i<apsums.size(); i++) {
cout << ds[i+1] << ": ";
for (int j=0; j<apsums[i].size(); j++) {
cout << apsums[i][j] << ' ';
}
cout << endl;
}
cout << endl;*/
//cout << "LEN APSUMS: " << apsums.size() << endl;
// add to apsums
// index from back ig = N-idx, if it's % isajfe = 0 then add
for (int i=0; i<N; i++) {
if (ds[i+1] == 0) continue;
//cout << "NEXT START" << endl;
//cout << N-idx-i << ' ' << (N-idx)%ds[i+1] << endl;
// it should be -( (N-idx)-(N-i) ) to get distance from idx to i --> basically idx-i
if (((idx-i-1)%ds[i+1]) == 0) {
//cout << apsums[i].size() << ", VAL: " << (apsums[i][apsums[i].size()-1]+res)%MOD << endl;
// add to the apsums
apsums[i].push_back((apsums[i][apsums[i].size()-1] + res)%MOD);
//cout << "YES " << i << " WHEN MAX " << N << endl;
}
//cout << "OKAY END" << endl;
}
//cout << "ADDED TO APSUMS" << endl;
}
/*cout << "DEBUG: ";
for (int i=1; i<=N; i++) {
cout << ress[i] << ' ';
}
cout << endl << endl;
cout << "APSUMS: " << endl;
for (int i=0; i<apsums.size(); i++) {
cout << ds[i+1] << ": ";
for (int j=0; j<apsums[i].size(); j++) {
cout << apsums[i][j] << ' ';
}
cout << endl;
}
cout << endl;*/
cout << ress[1] << '\n';
return 0;
}
