Write a C++ program that reads a three digit-integer and adds to it a fourth digit in the unit position to produce a valid bank PIN number. A valid bank PIN number is a four digit-integer has the property that the sum of its four digits is a multiple of 10. For example, if the number read is 725 then if we add to it in the unit position the digit 6 then we will have the new number 7256 with the property that 7+2+5+6 = 20 which is a multiple of 10. Sample Input/Output Enter a 3-digit integer: 725 The PIN number is 7256 Enter a 3-digit integer: 894 The PIN number is 8949 Enter a 3-digit integer: 659 The PIN number is 6590