#pragma GCC target ("avx2")
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pii;
#define all(x) x.begin(), x.end()
#define sz(x) ((int) ((x).size()))
#define pb push_back
#define F first
#define S second
#define FIO ios_base::sync_with_stdio(false); cin.tie(0)
const int K = 100;
const int N = 1e5 + K * 2;
const int MOD = 1e9 + 7;
ll potM(ll x, ll k) { if (k == 0) return 1; ll a = potM(x, k / 2); if (k % 2 == 0) { return (a * a) % MOD; } else { return ((a * a) % MOD * x) % MOD; }}
ll addM(ll a, ll b) { return a + b >= MOD ? a + b - MOD : a + b; }
ll subM(ll a, ll b) { return addM(a, MOD-b); }
ll mulM(ll a, ll b) { return a * b % MOD; }
ll divM(ll a, ll b) { return mulM(a, potM(b, MOD - 2)); }
int n;
ll d[N];
ll x[N];
ll dp[N];
ll dp2[N / K + 2][K + 5][K + 5];
inline ll query2(ll bu, ll off, ll po) {
if (off >= K) return 0;
if (po >= K) return dp[bu * K + off];
if (dp2[bu][off][po] != -1) return dp2[bu][off][po];
ll ind = bu * K + off;
ll ans = addM(query2(bu, off + po, po), dp[ind]);
dp2[bu][off][po] = ans;
return ans;
}
inline ll query(ll ind) {
ll bu = ind / K;
ll ci = d[ind];
ll br = x[ind];
if (ci == 0) return 1;
ll ans = 1;
ll cur = ind + ci;
ll broj = br;
while (cur / K == ind / K and cur < n and broj) {
ans = addM(ans, dp[cur]);
broj--;
cur += ci;
}
ll zad = bu;
ll end = ind + br * ci;
for (int i = bu + 1; i <= (n - 1) / K; i++) {
if (end < (i + 1) * K) {
zad = i;
break;
}
ll st = i * K;
ll off = (ind + (st - ind + ci - 1) / ci * ci) - st;
ll adding = query2(i, off, ci);
ans = addM(ans, adding);
}
ll st = zad * K;
broj = br - (st - ind + ci - 1) / ci;
cur = (st - ind + ci - 1) / ci * ci + ind;
while (zad != ind / K and cur < n and broj >= 0) {
ans = addM(ans, dp[cur]);
broj--;
cur += ci;
}
return ans;
}
int main() {
FIO;
memset(dp2, -1, sizeof dp2);
cin >> n;
for (int i = 0; i < n; i++) {
cin >> d[i] >> x[i];
}
for (int i = n - 1; i >= 0; i--) {
dp[i] = query(i);
}
cout << dp[0] << endl;
return 0;
}
