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

int main(void)
{
    srand((unsigned) time(NULL));
    
    printf("Upper case letter: %c\n", rand() % 26 + 65);
    printf("Lower case letter: %c\n", rand() % 26 + 97);
    
    return 0;
}