def sousedi(v,E):
    s1 = set( y for x,y in E if x==v )
    s2 = set( x for x,y in E if y==v )
    return [ z for z in s1+s2 ]

def najdi_cestu(n,E):
    E += [ (n,x) for x in range(n) ] + [ (n,n+1) ]
    cesta = [ n+1, n ]
    for kolo in range(n):
        kde = cesta[-1]
        kam_muzeme = sousedi( kde, E )
        kam_muzeme.remove( cesta[-2] )
        ostatni_hrany = [ x,y for x,y in E if x!=kde and y!=kde ] + \
	                [ (kde,cesta[-2]) ]
        while len(kam_muzeme) > 1:
            cnt = len(kam_muzeme)
            k1, k2 = kam_muzeme[:cnt//2], kam_muzeme[cnt//2:]
            if cesta( n+2, ostatni_hrany + [ (kde,x) for x in k1 ] ):
                kam_muzeme = k1
            else:
                kam_muzeme = k2
        vitez = kam_muzeme[0]
        cesta.append( vitez )
        E = ostatni_hrany + [ (kde,vitez) ]
    return cesta[2:]