#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <cmath>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <queue>
#include <stack>
#include <deque>
#include <limits>
#include <functional>
#include <utility>
#include <tuple>
#include <iomanip>
#include <sstream>
#include <fstream>
#include <random>
#include <chrono>
#include <bitset>
using namespace std;
using ll = long long; using db = double; using i128 = __int128_t;
template <class T> using v = vector<T>;
using pii = pair<int, int>; using vi = v<int>; using vpi = v<pii>; using vvi = v<vi>; using vvpi = v<vpi>;
using pll = pair<ll, ll>; using vll = v<ll>; using vpl = v<pll>; using vvl = v<vll>; using vvpl = v<vpl>;
#define mp make_pair
#define f first
#define s second
#define pb push_back
#define pf push_front
#define all(x) x.begin(), x.end()
const int INF = 1e9;
const ll INFLL = 1e18;
const ll MOD = 1'000'000'007;
const int N = 100005, K=330;
ll n, dp[N], d[N], x[N], dp2[K+1][K+1];
vi out[N];
signed main () {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cin >> n;
for (int i=1; i<=n; i++){
cin >> d[i] >> x[i];
}
ll ans = 0;
dp[1] = 1;
for (ll i=1; i<=n; i++){
for (ll j=1; j<=K; j++){
dp[i] += dp2[j][i % j];
dp[i] %= MOD;
}
if (d[i] > K){
for (ll j = i+d[i]; j<=i+x[i] * d[i]; j += d[i]){
dp[j] += dp[i];
dp[j] %= MOD;
}
}
else if (d[i] > 0){
ll op = min(n+1, i + x[i] * d[i]);
out[op].pb(i);
dp2[d[i]][i % d[i]] += dp[i];
dp2[d[i]][i % d[i]] %= MOD;
}
for (int j : out[i]){
dp2[d[j]][i % d[j]] -= dp[j];
dp2[d[j]][i % d[j]] += MOD;
dp2[d[j]][i % d[j]] %= MOD;
}
}
for (int i=1; i<=n; i++){
ans += dp[i];
ans %= MOD;
}
cout << ans << '\n';
return 0;
}
