GCD.java

import java.util.*;
public class main{
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        while(input.hasNext()) {
        	int result = 0;
        	int N = input.nextInt();
        	if(N == 0)
        		break;
        	for(int i=1;i<N;i++)
				for(int j=i+1;j<=N;j++) {
					//System.out.println(i + "," + j);
					//System.out.println(GCD(i,j));
					result += GCD(i,j);
				}
			
			System.out.println(result);
        }
    }
    
    public static int GCD(int num1, int num2) {
    	if(num2 > num1) {
    		int temp = num2;
    		num2 = num1;
    		num1 = temp;
    	}
    	
    	int result = 0;
    	while(num2 != 0) {
    		int temp = num1 % num2;
    		num1 = num2;
    		num2  = temp;
    		result = num1;
    	}
    	
    	if(result == 0)
    		return 1;
    	else
    		return num1;
    }
};