#include<iostream>#include<cstdio>#include<cmath>#include<cstring>#include<cstdlib>#include<iomanip>#include<algorithm>#include<ctime>#include<stack>#include<queue>#include<vector>#define N 100005using namespace std;int a[N],b[N];bool match(int len){ int i; for(i=0;i<len;i++) if(a[i]!=b[i]) return false; return true; }int main(){ int i,len; while(cin>>len&&len) { for(i=0;i<len;i++){cin>>a[i];b[a[i]-1]=i+1;} if(match(len))cout<<"ambiguous"<<endl; else cout<<"not ambiguous"<<endl; } return 0;}
