import java.util.*;
import java.lang.Math.*;
import java.math.BigDecimal;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		long syaink = sc.nextLong();
        BigDecimal ss = BigDecimal.valueOf(syaink);
        double syainj = sc.nextDouble();
        BigDecimal ssc =BigDecimal.valueOf(syainj);
      BigDecimal b3 = ss.multiply(ssc);
      BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN);
      System.out.println(result3);
}
} import java.util.*; util.* java import java.lang.Math.*; Math.* java.lang import java.math.BigDecimal; BigDecimal java.math public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		long syaink = sc.nextLong();
        BigDecimal ss = BigDecimal.valueOf(syaink);
        double syainj = sc.nextDouble();
        BigDecimal ssc =BigDecimal.valueOf(syainj);
      BigDecimal b3 = ss.multiply(ssc);
      BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN);
      System.out.println(result3);
}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		long syaink = sc.nextLong();
        BigDecimal ss = BigDecimal.valueOf(syaink);
        double syainj = sc.nextDouble();
        BigDecimal ssc =BigDecimal.valueOf(syainj);
      BigDecimal b3 = ss.multiply(ssc);
      BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN);
      System.out.println(result3);
} main {
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		long syaink = sc.nextLong();
        BigDecimal ss = BigDecimal.valueOf(syaink);
        double syainj = sc.nextDouble();
        BigDecimal ssc =BigDecimal.valueOf(syainj);
      BigDecimal b3 = ss.multiply(ssc);
      BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN);
      System.out.println(result3);
} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long syaink = sc.nextLong(); syaink sc.nextLong() sc.nextLong sc BigDecimal ss = BigDecimal.valueOf(syaink); ss BigDecimal.valueOf(syaink) BigDecimal.valueOf BigDecimal syaink double syainj = sc.nextDouble(); syainj sc.nextDouble() sc.nextDouble sc BigDecimal ssc =BigDecimal.valueOf(syainj); ssc BigDecimal.valueOf(syainj) BigDecimal.valueOf BigDecimal syainj BigDecimal b3 = ss.multiply(ssc); b3 ss.multiply(ssc) ss.multiply ss ssc BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN); result3 b3.setScale(0, BigDecimal.ROUND_DOWN) b3.setScale b3 0 BigDecimal.ROUND_DOWN BigDecimal BigDecimal.ROUND_DOWN System.out.println(result3) System.out.println System.out System System.out result3 String[] args args public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		long syaink = sc.nextLong();
        BigDecimal ss = BigDecimal.valueOf(syaink);
        double syainj = sc.nextDouble();
        BigDecimal ssc =BigDecimal.valueOf(syainj);
      BigDecimal b3 = ss.multiply(ssc);
      BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN);
      System.out.println(result3);
}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		long syaink = sc.nextLong();
        BigDecimal ss = BigDecimal.valueOf(syaink);
        double syainj = sc.nextDouble();
        BigDecimal ssc =BigDecimal.valueOf(syainj);
      BigDecimal b3 = ss.multiply(ssc);
      BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN);
      System.out.println(result3);
}
} Main
import java.util.*;
import java.lang.Math.*;
import java.math.BigDecimal;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// スペース区切りの整数の入力
		long syaink = sc.nextLong();
        BigDecimal ss = BigDecimal.valueOf(syaink);
        double syainj = sc.nextDouble();
        BigDecimal ssc =BigDecimal.valueOf(syainj);
      BigDecimal b3 = ss.multiply(ssc);
      BigDecimal result3 = b3.setScale(0, BigDecimal.ROUND_DOWN);
      System.out.println(result3);
}
}