#include "cave.h"
#include <bits/stdc++.h>
using namespace std;
#define f(i,a,b) for(int i = a; i < b; i++)
const int N = 5005;
/*
int s[N], d[N], p[N];
int n;
int tryCombination(int v[]){
f(i,0,n) if(v[p[i]] != s[p[i]]) return i;
return -1;
}
void answer(int si[], int di[]){
f(i,0,n){
if(si[i] != s[i] or di[i] != d[i]){
cout << "WA\n";
return;
}
}
cout << "AC\n";
}
*/
int v[N], S[N], D[N], inv[N];
int n;
void change(int l, int r){
f(i,l,r+1) if(D[i] == -1) v[i] = 1 - v[i];
}
int tri(int r[]){
int ans = tryCombination(r);
if(ans == -1) ans = n;
return ans;
}
void find(int x){
f(i,0,n) v[i] = 0;
f(i,0,x) v[inv[i]] = S[inv[i]];
int l = 0, r = n-1;
int val = tri(v);
int u;
if(val == x) u = 1;
else u = 0;
while(l < r){
int m = (l+r)>>1;
change(0, m);
int wi = tri(v);
if((wi > x and u == 1) or (wi == x and u == 0)) r = m;
else l = m+1;
change(0, m);
}
S[l] = u, D[l] = x, inv[x] = l;
}
void exploreCave(int ni) {
n = ni;
f(i,0,n) S[i] = D[i] = inv[i] = -1;
f(i,0,n)
find(i);
answer(S, D);
}
/*
int main(){
cin >> n;
f(i,0,n) cin >> s[i];
f(i,0,n) cin >> d[i], p[d[i]] = i;
exploreCave(n);
return 0;
}
*/
