import java.math.BigDecimal;
import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        double A = sc.nextDouble();
        double B = sc.nextDouble();
        sc.close();

        BigDecimal res = BigDecimal.valueOf(A).multiply(BigDecimal.valueOf(B));
        String val = res.toPlainString();
        int index = val.indexOf(".");
        if (index >= 0) {
            val = val.substring(0, index);
        }

        System.out.println(val);

    }
}
/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