#include <bits/stdc++.h>
#define ll long long
#define db long double
#define II pair <ll,ll>
#define III pair <ll,II>
#define IV pair <vector <int>,vector <int> >
#define TII pair <treap*,treap*>
#define fst first
#define snd second
#define BIT(x,i) ((x>>i)&1)
#define pi acos(-1)
#define to_radian(x) (x*pi/180.0)
#define to_degree(x) (x*180.0/pi)
#define Log(x) (31-__builtin_clz((int)x))
#define LogLL(x) (63-__builtin_clzll((ll)x))
#include "gondola.h"
using namespace std;
int n,i,a[100005];
int valid(int n,int a[])
{
int last_u=0,last_i=0;
map <int,int> d;
for(i=0;i<n;i++)
{
int u=a[i];
if(d[u]) return 0;
d[u]=1;
if(u>n) continue;
if(last_u>0 && (u-last_u+n)%n!=(i-last_i+n)%n)
return 0;
last_u=u; last_i=i;
}
return 1;
}
int replacement(int n, int gondolaSeq[], int replacementSeq[])
{
return -2;
}
//----------------------
int countReplacement(int n, int inputSeq[])
{
return -3;
}
/*
int main()
{
freopen("gondola.inp","r",stdin);
freopen("gondola.out","w",stdout);
cin>>n;
for(i=0;i<n;i++) cin>>a[i];
cout<<valid(n,a);
}
*/
