#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
using namespace std;
#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second
const int BLK = 200;
const int MOD = 1000000007;
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin>>n;
vector<int> dp(n+2, 0);
vector<pii> vect(n+1);
set<pii> temp;
temp.insert(mp(LLONG_MAX/2, 0));
vector<vector<set<pii> > > s(BLK, vector<set<pii> >(BLK, temp));
for (int i=1; i<=n; ++i)cin>>vect[i].fi>>vect[i].se, vect[i].se=min(vect[i].se, (n-i)/vect[i].fi);
for (int i=n; i>=1; --i){
dp[i]=1;
if (vect[i].fi>=BLK||vect[i].se<=BLK)for (int j=1; j<=vect[i].se; ++j)dp[i]=(dp[i]+dp[i+j*vect[i].fi])%MOD;
else if (vect[i].fi){
dp[i]=(dp[i]+s[vect[i].fi][i%vect[i].fi].begin()->se)%MOD;
auto it=s[vect[i].fi][i%vect[i].fi].upper_bound(mp(i+vect[i].fi*vect[i].se, LLONG_MAX/2));
dp[i]=(dp[i]+MOD-it->se)%MOD;
}
for (int j=1; j<BLK; ++j)s[j][i%j].insert(mp(i, (dp[i]+s[j][i%j].begin()->se)%MOD));
}
cout<<dp[1];
}
