Suppose that M and N are integers and M is non-zero. M is called a divisor of N if N =MT for some integer T that is when M divides N the remainder is zero. Moreover, M is called a proper divisor of N if M < N and M divides N. a positive integer is called perfect if it is the sum of its positive proper divisors. For example, the positive proper divisors of 28 are 1, 2, 4, 7, and 14 and 1+2+4+7+14=28. Therefore, 28 is perfect. Write a program that outputs the first four perfect integers.