import std;

void main() {
    long a; string b; scan(a, b);

    int x = b[0] - '0';
    int y = b[2] - '0';
    int z = b[3] - '0';

    long ans = a * 100 * x;
    ans += a * 10 * y;
    ans += a * z;
    writeln(ans / 100);
}

void scan(T...)(ref T a) {
    string[] ss = readln.split;
    foreach (i, t; T) a[i] = ss[i].to!t;
}
T read(T=string)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readints = reads!int;
