#include <bits/stdc++.h>
using namespace std;
const int maxn = 100005;
const int mod = 1e9 + 7;
int n;
int d[maxn], x[maxn];
int dp[maxn];
int pref[maxn];
void fastIO()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
int main()
{
fastIO();
cin >> n;
for (int i = 1; i <= n; ++i)
{
cin >> d[i] >> x[i];
}
if (n <= 10000)
{
dp[1] = 1;
int ans = 1;
for (int i = 2; i <= n; ++i)
{
for (int j = i - 1; j >= 1; --j)
{
if (d[j] != 0 && (i - j) % d[j] == 0 && (i - j) / d[j] <= x[j])
{
dp[i] += dp[j];
if (dp[i] >= mod) dp[i] -= mod;
}
}
ans += dp[i];
if (ans >= mod) ans -= mod;
}
cout << ans << endl;
return 0;
}
bool allD = true, allX = true;
for (int i = 1; i <= n; ++i)
{
allD &= (d[i] == 1);
allX &= (x[i] == 1000000000);
}
if (allD == true)
{
for (int i = 1; i <= n; ++i)
{
x[i] = min(x[i], n);
}
dp[1] = 1;
pref[1] = 1;
pref[x[1] + 2] = mod - 1;
int ans = 1;
for (int i = 2; i <= n; ++i)
{
pref[i] += pref[i - 1];
if (pref[i] >= mod) pref[i] -= mod;
dp[i] = pref[i];
ans += dp[i];
if (ans >= mod) ans -= mod;
pref[i + 1] += dp[i];
if (pref[i + 1] >= mod) pref[i + 1] -= mod;
pref[min(n + 1, i + x[i] + 1)] -= dp[i];
if (pref[min(n + 1, i + x[i] + 1)] < 0) pref[min(n + 1, i + x[i] + 1)] += mod;
//cout << i << " :: " << dp[i] << endl;
//cout << min(n + 1, i + x[i] + 1) << endl;
}
cout << ans << endl;
}
return 0;
}
/*
5
1 3
1 1
1 2
1 2
1 2
2 :: 1
3 :: 2
4 :: 3
5 :: 5
*/
