
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Main {
    public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] tokens = br.readLine().split(" ");
        long a = Long.parseLong(tokens[0]);
        long b = convertToLong(tokens[1]);
        long ans = (a*b)/100;
        System.out.println(ans);
    }

    private static long convertToLong(String s){
        long num = 0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        }
        return num;
    }

} import java.io.BufferedReader; BufferedReader java.io import java.io.InputStreamReader; InputStreamReader java.io public class Main {
    public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] tokens = br.readLine().split(" ");
        long a = Long.parseLong(tokens[0]);
        long b = convertToLong(tokens[1]);
        long ans = (a*b)/100;
        System.out.println(ans);
    }

    private static long convertToLong(String s){
        long num = 0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        }
        return num;
    }

} Main public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] tokens = br.readLine().split(" ");
        long a = Long.parseLong(tokens[0]);
        long b = convertToLong(tokens[1]);
        long ans = (a*b)/100;
        System.out.println(ans);
    } main {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] tokens = br.readLine().split(" ");
        long a = Long.parseLong(tokens[0]);
        long b = convertToLong(tokens[1]);
        long ans = (a*b)/100;
        System.out.println(ans);
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) String[] tokens = br.readLine().split(" "); tokens br.readLine().split(" ") br.readLine().split br.readLine() br.readLine br " " long a = Long.parseLong(tokens[0]); a Long.parseLong(tokens[0]) Long.parseLong Long tokens[0] tokens 0 long b = convertToLong(tokens[1]); b convertToLong(tokens[1]) convertToLong tokens[1] tokens 1 long ans = (a*b)/100; ans (a*b)/100 (a*b) a b 100 System.out.println(ans) System.out.println System.out System System.out ans String args[] args private static long convertToLong(String s){
        long num = 0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        }
        return num;
    } convertToLong {
        long num = 0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        }
        return num;
    } long num = 0; num 0 for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        } int i=0; int i=0; i 0 i<s.length() i s.length() s.length s i++ i++ i {
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        } {
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        } if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            } s.charAt(i)>='0' && s.charAt(i)<='9' s.charAt(i)>='0' s.charAt(i) s.charAt s i '0' s.charAt(i)<='9' s.charAt(i) s.charAt s i '9' {
                num=num*10 + (s.charAt(i)-'0');
            } num=num*10 + (s.charAt(i)-'0') num num*10 + (s.charAt(i)-'0') num*10 num 10 (s.charAt(i)-'0') s.charAt(i) s.charAt s i '0' return num; num String s s public class Main {
    public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] tokens = br.readLine().split(" ");
        long a = Long.parseLong(tokens[0]);
        long b = convertToLong(tokens[1]);
        long ans = (a*b)/100;
        System.out.println(ans);
    }

    private static long convertToLong(String s){
        long num = 0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        }
        return num;
    }

} public class Main {
    public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] tokens = br.readLine().split(" ");
        long a = Long.parseLong(tokens[0]);
        long b = convertToLong(tokens[1]);
        long ans = (a*b)/100;
        System.out.println(ans);
    }

    private static long convertToLong(String s){
        long num = 0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        }
        return num;
    }

} Main

import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Main {
    public static void main(String args[]) throws Exception {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] tokens = br.readLine().split(" ");
        long a = Long.parseLong(tokens[0]);
        long b = convertToLong(tokens[1]);
        long ans = (a*b)/100;
        System.out.println(ans);
    }

    private static long convertToLong(String s){
        long num = 0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)>='0' && s.charAt(i)<='9'){
                num=num*10 + (s.charAt(i)-'0');
            }
        }
        return num;
    }

}