import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigDecimal;

public class Main {
	static BigDecimal A;
	static BigDecimal B;
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		read();
	}

	private static void read() throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] word = br.readLine().split(" ");
		A = BigDecimal.valueOf(Double.valueOf(word[0]));
		B = BigDecimal.valueOf(Double.valueOf(word[1]));
		A = A.multiply(B);
		System.out.println(A.longValue());
		br.close();
	}

} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io import java.math.BigDecimal; BigDecimal java.math public class Main {
	static BigDecimal A;
	static BigDecimal B;
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		read();
	}

	private static void read() throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] word = br.readLine().split(" ");
		A = BigDecimal.valueOf(Double.valueOf(word[0]));
		B = BigDecimal.valueOf(Double.valueOf(word[1]));
		A = A.multiply(B);
		System.out.println(A.longValue());
		br.close();
	}

} Main static BigDecimal A; A static BigDecimal B; B public static void main(String[] args) throws NumberFormatException, IOException {
		read();
	} main {
		read();
	} read() read String[] args args private static void read() throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] word = br.readLine().split(" ");
		A = BigDecimal.valueOf(Double.valueOf(word[0]));
		B = BigDecimal.valueOf(Double.valueOf(word[1]));
		A = A.multiply(B);
		System.out.println(A.longValue());
		br.close();
	} read {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] word = br.readLine().split(" ");
		A = BigDecimal.valueOf(Double.valueOf(word[0]));
		B = BigDecimal.valueOf(Double.valueOf(word[1]));
		A = A.multiply(B);
		System.out.println(A.longValue());
		br.close();
	} BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) String[] word = br.readLine().split(" "); word br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " A = BigDecimal.valueOf(Double.valueOf(word[0])) A BigDecimal.valueOf(Double.valueOf(word[0])) BigDecimal.valueOf BigDecimal Double.valueOf(word[0]) Double.valueOf Double word[0] word 0 B = BigDecimal.valueOf(Double.valueOf(word[1])) B BigDecimal.valueOf(Double.valueOf(word[1])) BigDecimal.valueOf BigDecimal Double.valueOf(word[1]) Double.valueOf Double word[1] word 1 A = A.multiply(B) A A.multiply(B) A.multiply A B System.out.println(A.longValue()) System.out.println System.out System System.out A.longValue() A.longValue A br.close() br.close br public class Main {
	static BigDecimal A;
	static BigDecimal B;
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		read();
	}

	private static void read() throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] word = br.readLine().split(" ");
		A = BigDecimal.valueOf(Double.valueOf(word[0]));
		B = BigDecimal.valueOf(Double.valueOf(word[1]));
		A = A.multiply(B);
		System.out.println(A.longValue());
		br.close();
	}

} public class Main {
	static BigDecimal A;
	static BigDecimal B;
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		read();
	}

	private static void read() throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] word = br.readLine().split(" ");
		A = BigDecimal.valueOf(Double.valueOf(word[0]));
		B = BigDecimal.valueOf(Double.valueOf(word[1]));
		A = A.multiply(B);
		System.out.println(A.longValue());
		br.close();
	}

} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigDecimal;

public class Main {
	static BigDecimal A;
	static BigDecimal B;
	
	public static void main(String[] args) throws NumberFormatException, IOException {
		read();
	}

	private static void read() throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		String[] word = br.readLine().split(" ");
		A = BigDecimal.valueOf(Double.valueOf(word[0]));
		B = BigDecimal.valueOf(Double.valueOf(word[1]));
		A = A.multiply(B);
		System.out.println(A.longValue());
		br.close();
	}

}
