#include <stdio.h>

char s[] = "CIAO";

int L(char s[]) {
    int i;
    for(i=0; s[i] != '\0'; i++) {}
    return i;
}

int main() {
    printf("%s\n", s);
    printf("%d\n", L(s));
    s[3] = '\0';
    printf("%s\n", s);
    printf("%d\n", L(s));
}