# Grundrechenarten

# Eingabe der Operanden
print ('Operanden:')
x = int(input('x = '))
y = int(input('y = '))
print()

# Eingabe der Operation
print('Operation:')
print('  Addition < + >')
print('  Subtraktion < - >')
print('  Multiplikation < * >')
print('  Division < / >')
print('  Potenz < ** > ')
o = input()
print()

def summe(a,b):
      return a + b

def differenz(a,b):
      return a - b
          
def produkt(a,b):
      result = 0
      i = 0
      while i < b:
          result = summe(result,a)
          i +=1
      return result

def quotient(a,b):
      rest = a
      result = 0
      while rest >= b:
          rest = differenz(rest,b)
          result += 1
      return result

def potenz(a,b):
      if b == 0: return 1
      else:
        result = a
        i = 1
        while i < b:
          result = produkt(result,a)
          i +=1
        return result

if o == '+':
    print (x, ' + ', y, '=',summe(x,y))
elif o == '-':
    print (x, ' - ', y, '=',differenz(x,y))
elif o == '*':
    print (x, ' * ', y, '=',produkt(x,y))
elif o == '/':
    print (x, ' // ', y, '=',quotient(x,y))
elif o == '**':
    print (x, ' ^ ', y, '=',potenz(x,y))
else: print('falsche Eingabe')