/*
#include <stdio.h>
int main()
{
printf("Hello");
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
printf("Hello World");
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
printf("Hello\nWorld");
return 0;
}*/
/*
#include<stdio.h>
int main()
{
printf("\'hello world\"");
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
printf("\'Hello\'");
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
printf("\"Hello World\"");
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
printf("\"\!\@\#\$%%\^\&\*\()\"");
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
printf("\"C\:\\Download\\hello\.cpp\"");
return 0;
}
*/
/*
#include<stdio.h>
int main() {
int a, b, c;
scanf("%d", &a);
scanf("%d", &b);
scanf("%d %d", &a, &b);
c = a+b;
printf("%d+%d=%d", a,b,c);
}
*/
/*
#include<stdio.h>
int main()
{
int a, b;
scanf("%d %d", &a, &b);
printf("%d %d", a,b);
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
int a, b;
scanf("%d %d", &b, &a);
printf("%d %d", a,b);
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
int a, b, c;
scanf("%d %d",&a, &b);
c = a+b;
printf("%d", c);
return 0;
}
*/
/*
#include<stdio.h>
int main()
{
double a, b, c;
scanf("%lf %lf", &a, &b);
c = a*b/2;
printf("%.1lf",c);
}
*/
#include<stdio.h>
int main()
{
double a, b, c;
scanf("%lf %lf", &a, &b);
c = a*b;
printf("%.2lf",c);
}