import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		@SuppressWarnings("resource")
		Scanner sc = new Scanner(System.in);

		BigDecimal A = sc.nextBigDecimal();
		BigDecimal B = sc.nextBigDecimal();
		BigDecimal B2 = B.multiply(new BigDecimal(100.00));
		BigDecimal ans = A.multiply(B2);
		String str = null;
		if (new BigDecimal(100.00).compareTo(ans) <= 0) {
			str = ans.toString();
			int int1 = str.indexOf(".");
			if (int1 > -1) str = str.substring(0,int1);
			str = str.substring(0, str.length() - 2);
		} else {
			str = "0";
		}
		
		// 出力
		System.out.println(str);
	}
}

// String str1 = sc.next();　// Stringで取得
// int int1 = sc.nextInt();　// intで取得
// BigDecimal bd1 = sc.nextBigDecimal();　// BigDecimalで取得
// byte byte1 = sc.nextByte();　// byteで取得
// 
// 区切り文字　－＞　タブ、スペース、改行
/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