def toplama(a,b):
    return a+b
def cikarma(a,b):
    return a-b
def carpma(a,b):
    return a*b
def bolme(a,b):
    return a/b

def islem(f1,f2,f3,f4,islem_adi):
    if islem_adi=='toplama':
        print(f1(2,3))
    elif islem_adi=='cikarma':
        print(f2(5,4))
    elif islem_adi=='carpma':
        print(f3(2,3))
    elif islem_adi=='bolme':
        print(f4(10,5))
    else:
        print('geçersiz islem..')

islem(toplama,cikarma,carpma,bolme,'bolme')