Write a Python program that accepts an integer (n) and computes the value of n+nn+nnn

Introduction

Write a Python program that accepts an integer (n) and computes the value of n+nn+nnn. I have used python 3.7 compiler for debugging purpose.

a = int(input("Input an integer : "))
num1 = int( "%s" % a )
num2 = int( "%s%s" % (a,a) )
num3 = int( "%s%s%s" % (a,a,a) )
print (num1+num2+num3)