/*
 * C 言語演習問題(4) 再帰呼出し
 * 問題1 解答例
 * (C) 2005 Hirohisa AMAN <aman@ehime-u.ac.jp>
 */
#include <stdio.h>

int sum(int n){
  if ( n == 1 ){
    return 1;
  }

  return n + sum(n-1);
}

int main(void){
  int n;

  printf("n = ? ");
  scanf("%d", &n);

  printf("sum = %d\n", sum(n));

  return 0;
}