用JAVA做的第一道题..
import java.io.*;
import java.math.*;
import java.util.*;
import java.text.*;
public class Main
{
public static void main(String[] args)
{
Scanner cin = new Scanner (new BufferedInputStream(System.in));
int N, R;
while (cin.hasNext())
{
N = cin.nextInt();
R = cin.nextInt();
String result = Integer.toString(N, R);
System.out.println(result.toUpperCase());
}
}
}