/*
  MIPT, task #001
  "Maximum"
  12.09.2011
 */

#include <stdio.h>

#define MAX(a, b) (((a) > (b))? (a) : (b))

int main()
{
  int max, a;

  scanf ("%d", &max);
  while (1 == scanf ("%d", &a)) {
      max = MAX (max, a);
  }

  printf ("%d\n", max);
  return 0;
}