#include <bits/stdc++.h>
using namespace std;
size_t n;
uint X[1 << 19], Y[1 << 19];
uint64_t product = 1;
set<size_t> idx;
const uint MOD = 1e9 + 7;
uint power(uint a, uint b)
{
uint r = 1;
while(b)
{
if(b % 2) r = (uint64_t) r * a % MOD;
a = (uint64_t) a * a % MOD;
b /= 2;
}
return r;
}
uint inverse(uint x) { return power(x, MOD - 2); }
struct segment_tree
{
const size_t w = 1 << 19;
uint values[1 << 20];
void set(size_t pos, uint val)
{
values[pos += w] = val;
while(pos /= 2)
values[pos] = max(values[2*pos], values[2*pos+1]);
}
uint get(size_t l, size_t r)
{
uint result = 0;
for(l += w, r += w; l < r; l /= 2, r /= 2)
{
if(l % 2) result = max(result, values[l++]);
if(r % 2) result = max(result, values[--r]);
}
return result;
}
} treeY;
uint maxY(size_t l, size_t r)
{
return treeY.get(l, r);
}
uint compute()
{
uint64_t yj = Y[n-1], li = 1, lj = 1;
for(auto it = --idx.end(); *it > 0 and li < UINT_MAX; )
{
auto i = *it, i1 = *prev(it);
auto yi = maxY(i1, i);
if(yj * li < yi * lj)
yj = yi, lj = li;
li *= X[i1];
it = prev(it);
}
return product * inverse(lj) % MOD * yj % MOD;
}
int init(int _n, int x[], int y[])
{
n = _n;
copy(x, x + n, X);
copy(y, y + n, Y);
for(size_t i = 0; i < n; i++)
{
product = product * X[i] % MOD;
if(X[i] > 1) idx.insert(i);
}
idx.insert(0); idx.insert(n);
X[n] = 1;
return compute();
}
int updateX(int pos, int val)
{
product = product * inverse(X[pos]) % MOD * val % MOD;
if(pos and X[pos] > 1) idx.erase(pos);
if(val > 1) idx.insert(pos);
X[pos] = val;
return compute();
}
int updateY(int pos, int val)
{
Y[pos] = val;
treeY.set(pos, val);
return compute();
}
