#include <stdio.h>
//正の奇数nを引数とし,以下の正の奇数の和を求める関数
int rec(int n){
    if (n == 1){
        return 1;
    }else if(n==0){
    	return 0;
    }
    else{
        return rec(n-2)+n;
    }
}
int main(void) {
    int n = 12;
    printf("%d以下の正の奇数の和は%d\n", n
, rec
(n
)); 	return 0;
}
				I2luY2x1ZGUgPHN0ZGlvLmg+Ci8v5q2j44Gu5aWH5pWwbuOCkuW8leaVsOOBqOOBl++8jOS7peS4i+OBruato+OBruWlh+aVsOOBruWSjOOCkuaxguOCgeOCi+mWouaVsAppbnQgcmVjKGludCBuKXsKICAgIGlmIChuID09IDEpewogICAgICAgIHJldHVybiAxOwogICAgfWVsc2UgaWYobj09MCl7CiAgICAJcmV0dXJuIDA7CiAgICB9CiAgICBlbHNlewogICAgICAgIHJldHVybiByZWMobi0yKStuOwogICAgfQp9CmludCBtYWluKHZvaWQpIHsKICAgIGludCBuID0gMTI7CiAgICBwcmludGYoIiVk5Lul5LiL44Gu5q2j44Gu5aWH5pWw44Gu5ZKM44GvJWRcbiIsIG4sIHJlYyhuKSk7CglyZXR1cm4gMDsKfQ==