#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
int duza(char a){
char b='a';
b=toupper(a);
if (a==b){
   return 1;
   }
else {
   return 0;
   }
}

int main() {
FILE *f;
FILE *fp;
f=fopen ("lit.txt","r");
if (f==NULL){
   printf("zly plik");
}
fp=fopen ("zapis.txt","w");

char x;
while(feof(f)==0){
	x=fgetc(f);
	if(duza(x)){
		x=tolower(x);
	}
	else{
		x=toupper(x);
	}
	fprintf(fp,"%c",x);
	printf("%c",x);
}
fclose (f);
fclose (fp);
}





#include <stdlib.h>
#include <stdio.h>

int main(){
FILE *fp;
fp=fopen("zad.txt","r");

int x=0;

while(feof(fp)!=1){
  fgetc(fp);
  x++;
  printf("%c",fgetc(fp));

}
 fclose(fp);
printf("%d\n",x);

return 0;
}