#include <stdbool.h>

#define boolean bool
#define character char
#define integer int
#define loop for (;;)

typedef character * text;
typedef integer instruction(integer);

static boolean doesnothalt(instruction program, integer input)
{
    volatile text magic = (text)program + input;
    return (boolean)magic;
}

static integer function(integer input)
{
    if (doesnothalt(function, input))
        loop;
    else
        return 0;
}

integer main(integer count, text arguments[])
{
    return function(count ? arguments[count - 1][0] : 0);
}