    import java.util.*;
    import java.math.BigDecimal;
     
    public class Main {
        public static void main(String[] args) {
            Scanner sc = new Scanner(System.in);
            String a = sc.next();
            String b = sc.next();
            BigDecimal b1 = new BigDecimal(a);
            BigDecimal b2  = new BigDecimal(b);
             BigDecimal c = b1.multiply(b2);
             BigDecimal d = c.setScale(0,BigDecimal.ROUND_DOWN);
            System.out.println(d);
        }
    }
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz