#include <bits/stdc++.h>
#define int long long
#define vi vector<int>
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<
#define all(x) x.begin(),x.end()
using namespace std;
const int N = 3e5+1,inf = 2e18,MOD = 1e9+7;
int add(int x,int y) {
if (x+y >= MOD) return x+y-MOD;
return x+y;
}
const int B = 2;
int lazy[B+1][B]{};
void solve() {
int n;
cin >> n;
vi d(n+1),x(n+1);
for (int i=1;i<=n;i++) {
cin >> d[i] >> x[i];
}
vector<pair<pii,int>> upds[n+1];
vi dp(n+1,0);
int ans = 0;
for (int i=1;i<=n;i++) {
if (i>1){
for (auto it : upds[i]) lazy[it.ff.ff][it.ff.ss]=add(lazy[it.ff.ff][it.ff.ss],MOD-it.ss);
}
else dp[i] = 1;
for (int j=1;j<=B;j++) dp[i] = add(dp[i],lazy[j][i%j]);
ans = add(ans,dp[i]);
if (!d[i]) continue;
if (d[i]+i > n) continue;
if (d[i] > B) {
for (int j = i+d[i],ctr = 1;j<=n && ctr <= x[i];j+=d[i],ctr++) {
dp[j] = add(dp[j],dp[i]);
}
}
else {
lazy[d[i]][i%d[i]]=add(lazy[d[i]][i%d[i]],dp[i]);
if (i+(x[i]+1)*d[i] <= n) upds[i+(x[i]+1)*d[i]].push_back({{d[i],i%d[i]},dp[i]});
}
}
cout << ans << '\n';
}
signed main() {
ios_base::sync_with_stdio(0),cin.tie(0);
#ifdef Dodi
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t = 1;
// cin >> t;
while (t --> 0) solve();
}
