stairs with custom steps

def solve_any(end, X):
    solutions = [0]
    for _ in range(end, 0, -1):
        val = 0
        n = len(solutions)
        for el in X:
            if n == el:
                val += 1
            if n-el > 0:
                val += solutions[n-el]
        solutions.append(val)
    return solutions[-1]

a = solve_any(10, {1, 3, 5})
print(a)