#include #include int main(){ int ch; int line_count = 0; while((ch = getchar()) != EOF){ if(islower(ch)){ putchar(toupper(ch)); }else if(isupper(ch)){ putchar(tolower(ch)); }else{ putchar(ch); } if(ch == '\n'){ line_count++; } } printf("\nLines count: %d\n", line_count); return 0; }