#!/usr/local/bin/python3

def sum(n, i=1):
    if n <= 0:
        return n
    print(f"count     : {i} kai")
    total = n + sum(n-1, i+1)
    print(f"n         : {n}")
    print(f"n-1       : {n-1}")
    print(f"n + (n-1) : {total}")
    print('--------------')
    return total

print("sum(10) =", sum(10))