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

public class Main {
    public static void main(String[] args) throws Exception {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        }
    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.InputStreamReader; InputStreamReader java.io import java.math.BigDecimal; BigDecimal java.math public class Main {
    public static void main(String[] args) throws Exception {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        }
    }
} Main public static void main(String[] args) throws Exception {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        }
    } main {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        }
    } try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        } {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)) BufferedReader br = new BufferedReader(new InputStreamReader(System.in)) new BufferedReader(new InputStreamReader(System.in)) String[] in = br.readLine().split(" "); in br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " br.close() br.close br BigDecimal x = new BigDecimal(in[0]); x new BigDecimal(in[0]) BigDecimal y = new BigDecimal(in[1]); y new BigDecimal(in[1]) System.out.println(x.multiply(y).toBigInteger()) System.out.println System.out System System.out x.multiply(y).toBigInteger() x.multiply(y).toBigInteger x.multiply(y) x.multiply x y String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        }
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

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

public class Main {
    public static void main(String[] args) throws Exception {
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {

            String[] in = br.readLine().split(" ");

            br.close();

            BigDecimal x = new BigDecimal(in[0]);
            BigDecimal y = new BigDecimal(in[1]);

            System.out.println(x.multiply(y).toBigInteger());

        }
    }
}