#include<bits/stdc++.h>
#define endl '\n'
#define pb push_back
using namespace std;
const long long maxn = 2e5 + 10, maxx = 555;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
}
long long n;
long long d[maxn], x[maxn];
vector < long long > g[maxn], rem[maxn];
long long dp[maxn], act[maxx][maxx], ans = 0;
const long long mod = 1e9 + 7;
int main()
{
speed();
cin >> n;
long long v;
for (long long i = 1; i <= n; ++ i)
{
cin >> d[i] >> x[i];
if(!d[i])continue;
if(d[i] > 400)
{
for (int j = 1; j <= x[i]; ++ j)
{
int v = i + j * d[i];
if(v > n)break;
g[j].pb(i);
}
}
else
{
int l = (n - i) / d[i];
if(l < x[i])x[i] = l;
rem[i + x[i] * d[i]].pb(i);
}
}
dp[1] = 1;
ans = 1;
if(d[1] && d[1] <= 400)
{
act[d[1]][1 % d[1]] += dp[1];
act[d[1]][1 % d[1]] %= mod;
}
for (int i = 2; i <= n; ++ i)
{
for (auto e: g[i])
{
dp[i] += dp[e];
dp[i] %= mod;
}
for (int r = 1; r <= 400; ++ r)
{
int ost = i % r;
dp[i] += act[r][ost];
dp[i] %= mod;
}
ans += dp[i];
ans %= mod;
if(d[i] && d[i] <= 400)
{
act[d[i]][i % d[i]] += dp[i];
act[d[i]][i % d[i]] %= mod;
}
}
cout << ans << endl;
return 0;
}
