#39404: c++解題攻略超簡單


iant520jc@gmail.com (Ian Lin)


#include <iostream>

using namespace std;

 

int gcd(int m, int n){

while ((m%=n) && (n%=m));

return m+n;

}

int main(){

int N, i, j, G;

while (cin >> N){

if (N==0){

break;

}

G=0;

for (i=1; i<N; i++){

for (j=i+1; j<=N; j++){

G+=gcd(j, i);

}

}

cout << G <<endl;

}

}