#include<stdio.h>

int main(int argc, char** argv) {

  char* filename = "upper.c";
  FILE* fptr;
  char c;

  if (argc > 1)
    filename = argv[1];

  fptr = fopen(filename,"r");
  
  while((c = getc(fptr)) != EOF) {
    if (islower(c))
      c = toupper(c);
    
    printf("%c",c);
  }
}