C :

#include"stdio.h"
#include"math.h"

int main()

{     int a,b,c,max;
scanf("%d %d %d",&a, &b, &c);
if(a>=b) max=a;
else  max=b;
if(b>=c) max=b;
else if(c>=a) max=c;
else  max=a;
printf("%d",max);
return 0;
}

C++ :

#include <cstdio>
#include <cmath>
int main (void)
{
	int a,b,c;
	scanf("%d%d%d",&a,&b,&c);
	if(a<=b&&b<=c)
		printf("%d\n",c);
	else if(b<=a&&a<=c)
		printf("%d\n",c);
	else if(a<=c&&c<=b)
		printf("%d\n",b);
    else if(c<=a&&a<=b)
		printf("%d\n",b);
	else if(b<=c&&c<=a)
		printf("%d\n",a);
	else printf("%d\n",a);
	return 0;
}

Pascal :

program aa;
var a,b,c,d,e,f,g:integer;
function domax(a,b:integer):integer;
var s:integer;
begin
 if a>b then s:=a
 else s:=b;
 domax:=s;
 end;

 begin
 read(a,b,c);
 d:=domax(a,b);
 e:=domax(d,c);
 write(e);
end.

Python :

# coding=utf-8
s = input(). split()
print(max(max(int(s[0]), int(s[1])), int(s[2])))