poj2470

#include

int main(){

int n;

while(scanf("%d",&n)&&n>=1&&n<=100000){

int i,a[100005]={0};

for(i=1;i<=n;i++) scanf("%d",&a[i]);

for(i=1;i<=n;i++)

 if(a[a[i]]!=i) break;

 if(i>n) printf("ambiguous\n");

 else printf("not ambiguous\n");

}

return 0;

}