#include <bits/stdc++.h>
#define pb push_back
#define int long long
using namespace std;
const int N = 3e5 + 5;
const int K = 20;
const int mod = 1e9 + 7;
struct SEGT{
vector<int> tree;
void init(int n){
tree.assign(4*n, 0);
}
void update(int ind, int l, int r, int pos, int val){
if(l == r){
tree[ind] = (tree[ind] + val + mod)%mod;
}
else{
int m = (l + r)/2;
if(pos <= m) update(ind*2, l, m, pos, val);
else update(ind*2+1, m+1, r, pos, val);
tree[ind] = (tree[ind*2] + tree[ind*2+1])%mod;
}
}
int query(int ind, int l, int r, int ql, int qr){
if(l > r || l > qr || r < ql) return 0;
if(l >= ql && r <= qr) return tree[ind];
else{
int m = (l + r)/2;
return (query(ind*2, l, m, ql, qr) + query(ind*2+1, m+1, r, ql, qr))%mod;
}
}
};
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int L = 200;
vector<SEGT> seg(L + 5);
for(int i = 1; i <= L; i++){
seg[i].init(i);
}
int n;
cin>>n;
vector<array<int, 3> > updlist[n+5];
vector<int> d(n+1), x(n+1), dp(n+1);
for(int i = 1; i <= n; i++){
cin>>d[i]>>x[i];
}
dp[1] = 1;
int ans = 0;
for(int i = 1; i <= n; i++){
for(auto itr: updlist[i]){
seg[itr[0]].update(1, 1, itr[0], itr[1], itr[2]);
}
for(int j = 1; j <= L; j++){
int pos = (i % j == 0 ? j : (i%j));
dp[i] = (dp[i] + seg[j].query(1, 1, j, pos, pos))%mod;
}
ans += dp[i];
ans %= mod;
if(d[i] == 0 || x[i] == 0) continue;
if(d[i] > L){
for(int j = 1; j <= x[i]; j++){
if(i + j * d[i] > n) break;
dp[i + j * d[i]] += dp[i];
dp[i + j * d[i]] %= mod;
}
}
else{
int last = i + x[i] * d[i] + 1;
int pos = (i % d[i] == 0 ? d[i] : (i%d[i]));
seg[d[i]].update(1, 1, d[i], pos, dp[i]);
if(last <= n) updlist[last].pb({d[i], pos, -dp[i]});
}
}
cout<<ans<<endl;
return 0;
}
