C :

#include <stdio.h>

int main(void) {
	double a, b, c;
	scanf("%lf%lf%lf", &a, &b, &c);
	if(a > b && a > c)
		printf("%.2lf", a);
	if(b > a && b > c)
		printf("%.2lf", b);
	else
		printf("%.2lf", c);
	return 0;
}

C++ :

#include<cstdio>
using namespace std;
int main()
{
	double a,b,c;
	scanf("%lf%lf%lf",&a,&b,&c);
	if(a>=b&&a>=c)
	{
		printf("%.2lf",a);
	}
	else if(b>=a&&b>=c)
	{
		printf("%.2lf",b);
	}
	else
	{
		printf("%.2lf",c);
	}
	return 0;
}

Pascal :

program zcczjyx;
  var
    a,b,c:real;
  begin
    read(a,b,c);
    if (a>=b) and (a>=c) then write(a:0:2)
                                  else  if (a<=b) and (b>=c) then write(b:0:2)
                                                                       else write(c:0:2);
  end.