everest% a.out Recursion depth = 0 Recursion depth = 1 Recursion depth = 2 Recursion depth = 3 Recursion depth = 4 Recursion depth = 5 Recursion depth = 6 Recursion depth = 7 Recursion depth = 8 Recursion depth = 9 Recursion depth = 10 Recursion depth = 11 Recursion depth = 12 Recursion depth = 13 Recursion depth = 14 Recursion depth = 15 Recursion depth = 16 Recursion depth = 17 Recursion depth = 18 Recursion depth = 19 Recursion depth = 20 . . . .