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

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        BigDecimal a = new BigDecimal(st.nextToken());
        BigDecimal b = new BigDecimal(st.nextToken());

        BigDecimal prod = a.multiply(b);
        prod = prod.setScale(0, BigDecimal.ROUND_DOWN);

        pw.println(prod);
        pw.close();
    }
} import java.io.*; io.* java import java.math.BigDecimal; BigDecimal java.math import java.util.StringTokenizer; StringTokenizer java.util public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        BigDecimal a = new BigDecimal(st.nextToken());
        BigDecimal b = new BigDecimal(st.nextToken());

        BigDecimal prod = a.multiply(b);
        prod = prod.setScale(0, BigDecimal.ROUND_DOWN);

        pw.println(prod);
        pw.close();
    }
} Main public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        BigDecimal a = new BigDecimal(st.nextToken());
        BigDecimal b = new BigDecimal(st.nextToken());

        BigDecimal prod = a.multiply(b);
        prod = prod.setScale(0, BigDecimal.ROUND_DOWN);

        pw.println(prod);
        pw.close();
    } main {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        BigDecimal a = new BigDecimal(st.nextToken());
        BigDecimal b = new BigDecimal(st.nextToken());

        BigDecimal prod = a.multiply(b);
        prod = prod.setScale(0, BigDecimal.ROUND_DOWN);

        pw.println(prod);
        pw.close();
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out)); pw new PrintWriter(new OutputStreamWriter(System.out)) StringTokenizer st = new StringTokenizer(br.readLine()); st new StringTokenizer(br.readLine()) BigDecimal a = new BigDecimal(st.nextToken()); a new BigDecimal(st.nextToken()) BigDecimal b = new BigDecimal(st.nextToken()); b new BigDecimal(st.nextToken()) BigDecimal prod = a.multiply(b); prod a.multiply(b) a.multiply a b prod = prod.setScale(0, BigDecimal.ROUND_DOWN) prod prod.setScale(0, BigDecimal.ROUND_DOWN) prod.setScale prod 0 BigDecimal.ROUND_DOWN BigDecimal BigDecimal.ROUND_DOWN pw.println(prod) pw.println pw prod pw.close() pw.close pw String[] args args public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        BigDecimal a = new BigDecimal(st.nextToken());
        BigDecimal b = new BigDecimal(st.nextToken());

        BigDecimal prod = a.multiply(b);
        prod = prod.setScale(0, BigDecimal.ROUND_DOWN);

        pw.println(prod);
        pw.close();
    }
} public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        BigDecimal a = new BigDecimal(st.nextToken());
        BigDecimal b = new BigDecimal(st.nextToken());

        BigDecimal prod = a.multiply(b);
        prod = prod.setScale(0, BigDecimal.ROUND_DOWN);

        pw.println(prod);
        pw.close();
    }
} Main
import java.io.*;
import java.math.BigDecimal;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(new OutputStreamWriter(System.out));

        StringTokenizer st = new StringTokenizer(br.readLine());
        BigDecimal a = new BigDecimal(st.nextToken());
        BigDecimal b = new BigDecimal(st.nextToken());

        BigDecimal prod = a.multiply(b);
        prod = prod.setScale(0, BigDecimal.ROUND_DOWN);

        pw.println(prod);
        pw.close();
    }
}
