pvjc24/cv1/program.c

#include <stdio.h>

int main() {
    int c = 0; 
    int lines_count = 0;

    while ((c = getchar()) != EOF) {
     
        if (c >= 'a' && c <= 'z') {
          
            c = c - 'a' + 'A';
        }
       
        else if (c >= 'A' && c <= 'Z') {
          
            c = c - 'A' + 'a';
        }
     
        else if (c == '\n') {
          
            lines_count++;
         
            putchar('\n');
        }
       
        putchar(c);
    }

   
    printf("Lines count: %d\n", lines_count);

    return 0;
}