#include<stdio.h>
#define size 100000
int a[size+1],b[size+1];
int main()
{
int i,j,c;long n;
while(1)
{ c=0;
scanf("%ld",&n);
if (n==0)
return;
for (i=1;i<=n;i++)
{
scanf("%d",&a[i]);
}
for (i=1;i<=n;i++)
{
j=a[i];
b[j]=i;
}
for (j=1;j<=n;j++)
{ if (a[j]==b[j])
c++;
else
break;
}
if(c==n)
printf("ambiguous \n");
else
printf("not ambiguous \n");
}
getch();
return 0;
}
question in ambiguous permutation in practice problems -> easy