#include <bits/stdc++.h>
#include "horses.h"
using namespace std;
const int MOD = 1e9 + 7;
vector<int> X, Y;
vector<long long> product;
long long max_profit;
int modInv(int a) {
int b = MOD - 2, res = 1;
while (b > 0) {
if (b & 1)
res = (1LL * res * a) % MOD;
a = (1LL * a * a) % MOD;
b >>= 1;
}
return res;
}
void computeMax() {
max_profit = 0;
for (int i = 0; i < (int)product.size(); ++i) {
long long current = (product[i] * Y[i]) % MOD;
if (current > max_profit)
max_profit = current;
}
}
int init(int N, int* x, int* y) {
X.resize(N);
Y.resize(N);
product.resize(N);
for (int i = 0; i < N; ++i) {
X[i] = x[i];
Y[i] = y[i];
}
product[0] = X[0] % MOD;
for (int i = 1; i < N; ++i) {
product[i] = (product[i-1] * X[i]) % MOD;
}
computeMax();
return max_profit % MOD;
}
int updateX(int pos, int val) {
int old_val = X[pos];
X[pos] = val % MOD;
int inv_old = modInv(old_val);
long long ratio = (1LL * val * inv_old) % MOD;
product[pos] = (product[pos] * ratio) % MOD;
for (int i = pos + 1; i < (int)product.size(); ++i) {
product[i] = (product[i] * ratio) % MOD;
}
computeMax();
return max_profit % MOD;
}
int updateY(int pos, int val) {
Y[pos] = val % MOD;
computeMax();
return max_profit % MOD;
}
