C++ :

#include<stdio.h>
int max(int a,int b)
{
	return a>b?a:b;
}
int main()
{
	int maxnum=0,temp;
	while(scanf("%d",&temp)!=EOF)
	{
		maxnum=temp;
		while(scanf("%d",&temp)!=EOF&&temp)
		{
			maxnum=max(maxnum,temp);
		}
		printf("%d\n",maxnum);
	}
	return 0;
}

Pascal :

var
a,max:longint;
begin
 while not eof do
 begin
  a:=1;
  max:=-999;
  while a<>0 do
  begin
  read(a);
  if a>max then max:=a;
  end;
  writeln(max);
  end;
  end.