#include <stdio.h>
#include <stdlib.h>

typedef struct cvor
{
	int br;
	struct cvor *l, *d;
	int balans;
} cvor;

//2Д приказ стабла
void razmak( char c, int n )
{
    while ( n -- ) putchar( c );
}

void vizuelniPrikaz_( cvor *koren, int nivo )
{
    if ( !koren )
    {
        razmak('\t', nivo );
        puts("~");
    }
    else
    {
        vizuelniPrikaz_( koren -> d, nivo + 1 );
        razmak('\t', nivo );
        printf("%d\n", koren -> br );
        vizuelniPrikaz_( koren -> l, nivo + 1 );
    }
}

void vizuelniPrikaz( cvor *koren )
{
	vizuelniPrikaz_( koren, 0 );
}

cvor *noviCvor( int x )
{
	cvor *novi = ( cvor * ) malloc( sizeof( cvor ) );
	novi -> br = x;
	novi -> l = novi -> d = NULL;
	novi -> balans = 0;
	
	return novi;
}

int max( int x, int y )
{
	return x > y ? x : y;
}

int dubina( cvor *t )
{
	if( !t ) return 0;
	return 1 + max( dubina( t -> l ), dubina( t -> d ) );
}

void dRotacija( cvor **t )
{
	cvor *pomd = *t;
	cvor *poml = pomd -> l;
	pomd -> l = poml -> d;
	poml -> d = pomd;
	*t = poml;
	
	poml -> balans = dubina( poml -> d ) - dubina( poml -> l );
	pomd -> balans = dubina( pomd -> d ) - dubina( pomd -> l );
}

void lRotacija( cvor **t )
{
	cvor *poml = *t;
	cvor *pomd = poml -> d;
	poml -> d = pomd -> l;
	pomd -> l = poml;
	*t = pomd;
	
	poml -> balans = dubina( poml -> d ) - dubina( poml -> l );
	pomd -> balans = dubina( pomd -> d ) - dubina( pomd -> l );
}

int dodaj( cvor **koren, int x )
{
	cvor *t = *koren;
	
	if( !t )
	{
		t = noviCvor( x );
		*koren = t;
		return 1;
	}
	
	int inc;
	if( x > t -> br ) inc = dodaj( &t -> d, x );
	else inc = -dodaj( &t -> l, x );
	
	t -> balans += inc;
	
	if( inc && t -> balans )
		if( t -> balans < -1 )
			if( t -> l -> balans < 0 ) dRotacija( &t );
			else
			{
				lRotacija( &t -> l );
				dRotacija( &t );	
			}
		else if( t -> balans > 1 )
			if( t -> d -> balans > 0 ) lRotacija( &t );
			else
			{
				dRotacija( &t -> d );
				lRotacija( &t );	
			}
		else return 1;
		
	*koren = t;
	return 0;
}

cvor *unos()
{
	cvor *koren = NULL;
	
	int x;
	scanf("%d", &x );
	while( x )
	{
		dodaj( &koren, x );
		scanf("%d", &x );
	}
	
	return koren;
}


int brCvorova( cvor *koren, int *idealno )
{
	if( !idealno ) return;
	if( !koren ) return 0;
	
	int l = brCvorova( koren -> l, idealno );
	int d = brCvorova( koren -> d, idealno );
	
	if( l == d ) return 1 + l + d;
	*idealno = 0;
}

int daLiJeStabloIdealno( cvor *koren )
{
	int idealno = 1;
	brCvorova( koren, &idealno );
	
	return idealno;
}

int main()
{
	cvor *koren = unos();
	
	vizuelniPrikaz( koren );
	
	if( daLiJeStabloIdealno( koren ) ) printf("Idealno je.\n");
	else printf("Nije idealno.\n");
	return 0;
}