'''
Write a python program to find sum of the first n positive integers. 
sum = (n*(n+1))/2

'''
positive_n_numb = int(input("Enter the positive number to get sum of it : "))
sum = (positive_n_numb*(positive_n_numb+1))/2

print(f"The sum of {positive_n_numb} is {sum}.")
