Write a program that, for a given two integer numbers N and X, calculates the sum S = 1 + 1!/X + 2!/X2 + ... + N!/XN 2. Write a program that reads a number N and calculates the sum of the first N members of the sequence of Fibonacci: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, ... Each member of the Fibonacci sequence (except the first two) is a sum of the previous two members. 4. Write a program that calculates the greatest common divisor (GCD) of given two numbers. Use the Euclidean algorithm (find it in Internet).