大数取余

import java.util.*;
import java.math.*;
class Main
{
    public static void main(String args[])
    {
        Scanner cin=new Scanner(System.in);
        BigInteger a,b;
        a=BigInteger.valueOf(1);
        b=BigInteger.valueOf(1);
        while(cin.hasNextBigInteger())
        {
            a=cin.nextBigInteger();
            b=cin.nextBigInteger();
            System.out.println(a.mod(b));
        }
    }
}