#include <stdlib.h>
#include <stdio.h>
#include <float.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

void main(int argc, char* argv[])
{
  float *array = NULL;
  int arrayLength = 0;
  int arrayUsage = 0;

  float max = FLT_MIN;
  float current;

  FILE *fp;

  for (int i = 1; i < argc; i++)
    {
      fp = fopen(argv[i], "r");
      if (fp == NULL)
        {
          fprintf(stderr, "Could not open `%s´: %s\n", argv[i], strerror(errno));
          exit(EXIT_FAILURE);
        }

      for (int res; res = fscanf(fp, "%f\n", &current); )
        {
          if (res == EOF || res != 1)
            break;

          if (arrayUsage >= arrayLength)
            {
              if (arrayLength <= 1)
                arrayLength = 1;

              // fprintf(stderr, "Reallocating array %d → %d\n", arrayLength, arrayLength * 2);
              arrayLength *= 2;
              array = realloc(array, sizeof(float) * arrayLength);
            }

          array[arrayUsage] = current;
          arrayUsage++;
        }
      
      if (ferror(fp))
        {
          fprintf(stderr, "Error while reading from file `%s´: %s\n", argv[i], strerror(errno));
          exit(EXIT_FAILURE);
        }

      fclose(fp);
    }

  for (int i = 0; i < arrayUsage; i++)
    {
      if (array[i] > max)
        max = array[i];
    }

  printf("%.2f\n", max);
}