C :

#include<stdio.h>
int main()
{
  int a,b,c;
  scanf("%d%d%d",&a,&b,&c);
  printf("%d\n",(a>b?a:b)>c?(a>b?a:b):c);
  return 0;
}

C++ :

#include<iostream>
using namespace std;
int main()
{
  int a,b,c,max;
  cin>>a>>b>>c;
  max=a;
  if(max<b)
    max=b;
  if(max<c)
    max=c;
  cout<<max<<endl;  
}

Pascal :

var a,b,c:longint;
begin
  readln(a,b,c);
  if a>=b then if a>=c then writeln(a);
  if b>a then if b>=c then writeln(b);
  if c>a then if c>b then writeln(c);
end.