a=int(input())
c=''
while a>0:
    yu=a%16
    if yu<10:
        c = c + str(yu)
    else:
        if yu==10:
            c += 'A'
        elif yu==11:
            c += 'B'
        elif yu==12:
            c += 'C'
        elif yu==13:
            c += 'D'
        elif yu==14:
            c += 'E'
        elif yu==15:
            c += 'F'
    a = a//16
print(c[::-1])