#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
#include <bits/stdc++.h>
#define int long long
#define pb push_back
#define fi first
#define se second
#define el cout << '\n';
using namespace std;
const int N = 1e5+5;
const int inf = 1e18;
const int LG = 31;
const int MOD = 1e9+7;
//const int mod = 998244353;
int n;
vector<int> g[N];
int dp[N],d[N],x[N];
int cnt=0;
int st[4*N],lazy[4*N];
void build(int id, int l, int r) {
if (l == r) {
st[id] = dp[l] % MOD;
return;
}
int mid = (l + r) / 2;
build(id * 2, l, mid);
build(id * 2 + 1, mid + 1, r);
st[id] = (st[id * 2] + st[id * 2 + 1]) % MOD;
}
void push(int id, int l, int r) {
if (lazy[id] != 0) {
st[id] = (st[id] + lazy[id] * (r - l + 1)) % MOD;
if (l != r) {
lazy[id * 2] = (lazy[id * 2] + lazy[id]) % MOD;
lazy[id * 2 + 1] = (lazy[id * 2 + 1] + lazy[id]) % MOD;
}
lazy[id] = 0;
}
}
void update(int id, int l, int r, int u, int v, int val) {
push(id, l, r);
if (l > v || u > r) return;
if (l >= u && r <= v) {
lazy[id] = (lazy[id] + val) % MOD;
push(id, l, r);
return;
}
int mid = (l + r) / 2;
update(id * 2, l, mid, u, v, val);
update(id * 2 + 1, mid + 1, r, u, v, val);
st[id] = (st[id * 2] + st[id * 2 + 1]) % MOD;
}
int get(int id, int l, int r, int u, int v) {
push(id, l, r);
if (l > v || u > r) return 0;
if (l >= u && r <= v) {
return st[id] % MOD;
}
int mid = (l + r) / 2;
return (get(id * 2, l, mid, u, v) + get(id * 2 + 1, mid + 1, r, u, v)) % MOD;
}
void solve(){
cin>>n;
for(int i=1; i<=n; i++){
cin>>d[i]>>x[i];
if(d[i]==1) cnt++;
if(d==0) continue;
}
if(cnt==n){
// cout << "dm\n";
fill(dp+1,dp+1+n,0);
dp[1]=1;
build(1,1,n);
for(int i=1; i<n; i++){
int v = get(1,1,n,i,i);
// cout << v << '\n';
if(x[i]==0) continue;
update(1,1,n,i+1,min(n,i+x[i]),v);
for(int j=1; j<=n; j++){
// cout << get(1,1,n,j,j) << ' ';
}
// el;
}
cout << get(1,1,n,1,n)%MOD;
return;
}
for(int i=1; i<=n; i++){
if(d[i]==0) continue;
for(int j=i+d[i]; j<=min(i+d[i]*x[i],n); j+=d[i]){
g[i].pb(j);
}
}
dp[1]=1;
for(int i=1; i<n; i++){
for(auto x:g[i]){
dp[x] = (dp[x]+dp[i])%MOD;
}
}
int ans=0;
for(int i=1; i<=n; i++){
ans+=dp[i];ans%=MOD;
}
cout << ans;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int t = 1;
// cin >> t;
while (t--) {
solve();
el;
}
}
