num1 = int(input("enter the first number"))
num2 = int(input("enter the second number"))
num3 = int(input("enter the third number"))
num4 = int(input("enter the fourth number"))

def bignumber(num1=10,num2=20,num3=30,num4=40):
    print(max(num1,num2,num3,num4))

bignumber(num1,num2,num3,num4)
