zoj 2795

#include <stdio.h>
#define MAX 100000
int main()
{
	int a[MAX], i, b[MAX], num, s, flag;
	while( scanf( "%d", &num ) && num )
	{
		flag = 1;
		s = 1;
		for( i = 0; i < num; i++ )
		{
			scanf( "%d", &a[i] );
			b[a[i]-1] = s++;
		}
		for( i = 0; i < num; i++ )
			if( a[i] != b[i] )
				flag = 0;
		if( flag )
			printf( "ambiguous\n" );
		else
			printf( "not ambiguous\n" );
	}
	return 0;
}