#include <bits/stdc++.h>
using namespace std;
typedef long long un;
typedef vector<un> vuc;
#define REP(i, a, b) for (un i = (un)a; i < (un)b; i++)
#define FEAC(i, a) for (auto&& i : a)
#define vec vector
#define ALL(x) (x).begin(), (x).end()
constexpr un M = 1e9 + 7;
#define DIRECT 0
#define CACHE 1
constexpr double alpha = 2;
vuc create_iv(un N){
un vel = 2;
while(vel < N) vel *= 2;
vuc iv(2*vel, 0);
iv[0] = vel;
return iv;
}
un get_iv(vuc& iv, un index){
un ret = 0;
index += iv[0];
while(index > 0){
ret += iv[index];
ret %= M;
index /= 2;
}
return ret;
}
void set_iv(vuc& iv, un L, un R, un val){
R = min(R, iv[0]-1);
L += iv[0];
R += iv[0];
while (L <= R)
{
if (L % 2 == 1){
iv[L] += val;
iv[L] %= M;
L++;
}
if (R % 2 == 0){
iv[R] += val;
iv[R] %= M;
R--;
}
L /= 2;
R /= 2;
}
}
int main(){
un N;
cin >> N;
vuc D(N);
vuc X(N);
REP(i, 0, N){
cin >> D[i] >> X[i];
}
un bound = (un)alpha*pow((double)N, 0.6666666);
map<pair<un, un>, un> vyskyty;
REP(i, 0, N){
if (D[i] == 0) continue;
if (vyskyty.find({D[i], i % D[i]}) == vyskyty.end()){
vyskyty[{D[i], i % D[i]}] = min(X[i], (N-i) / D[i]);
}
else{
vyskyty[{D[i], i % D[i]}] += min(X[i], (N-i) / D[i]);
}
}
map<pair<un, un>, un> volba;
FEAC(kv, vyskyty){
pair<un, un> key;
un val;
tie(key, val) = kv;
if (val < bound){
volba[key] = DIRECT;
}
else{
volba[key] = CACHE;
}
}
vuc DP(N, 0);
DP[0] = 1;
map<un, map<un, vuc>> cache;
REP(i, 0, N){
FEAC(kv, cache){
un key;
tie(key, ignore) = kv;
if (cache[key].find(i % key) != cache[key].end()){
DP[i] = (DP[i] + get_iv(cache[key][i % key], i/key)) % M;
}
}
if (D[i] == 0) continue;
if (volba[{D[i], i%D[i]}] == DIRECT){
for (un j = i + D[i]; (j < N) and (((j-i) / D[i]) <= X[i]); j += D[i]){
DP[j] = (DP[j] + DP[i]) % M;
}
}
else{
if (cache.find(D[i]) == cache.end()) {
cache[D[i]] = {{i % D[i], create_iv((N/D[i]) + 1)}};
}
else if (cache[D[i]].find(i % D[i]) == cache[D[i]].end()){
cache[D[i]][i % D[i]] = create_iv((N/D[i]) + 1);
}
set_iv(cache[D[i]][i % D[i]], (i/D[i]) + 1, (i/D[i]) + X[i], DP[i]);
}
}
un res = 0;
REP(i, 0, N){
res = (res + DP[i]) % M;
}
cout << res;
}
