#Write a function sum that has two parameters, a and b,  and function finds and 
#returns the sum of the parameters
#Write main to test your function 
#function definition
def sum(a,b): #sum is a name of the function; a and b are formal parameters
	total=a+b
	return total
def main():
	#Testing function sum
	#Test 1: we will call the function with actual parameters 5 and 7
	function_result=sum(5,7)
	#this line will first call function sum replacing a with 5 and b with 7
	#then function sum will be executed, total=5+7=12
	#then function sum will return 12 to the main function and the value 12 
	#will be assigned to variable function_result
	print("Function use Example 1:", function_result)
	#Test 2: we will first read two integers (user input)
	#then call function sum to find the sum of inputs
	#we can use the same variable names for actual and formal parameters
	a=int(input("enter first integer "))
	b=int(input("enter second integer "))
	#these a and b are NOT the same a and b we used in function definition
	#these a and b have "last name" main
	#and in function sum they had "last name" sum
	function_result1=sum(a,b)
	print("Function use Example 2:", function_result1)
	#Test 3: we will first read two integers (user input)
        #then call function sum to find the sum of inputs
	#This time we will use different variable names for actual parameters
	#we will call the function inside print statement
	num1=int(input("enter num1 "))
	num2=int(input("enter num2 "))
	print("Function use Example 3:", sum(num1, num2))

	#Test 4: we will first read two floats (user input) 
	#then call function sum to find the sum of inputs
	a=float(input("enter float "))
	b=float(input("enter float "))
	function_result2=sum(a,b)
	print("Function use Example 4:", function_result2)

	#Test 5: we will first read two strings (user input)
	#then call function sum to find the sum of inputs but in this case it 
	#will be a string constructed from first and second input
	name1=input("enter first string ")
	name2=input("enter second string ")
	print("Function use Example 5:", sum(name1, name2)) 
main()