#include <stdio.h>

void abort(void);
void exit(int);

int g(void) {
    return '\n';
}

void f(void) {
    char s[] = "abcedfg012345";
    char *sp = s + 12;

    switch (g()) {
    case '\n':
        break;
    }

    while (*--sp == '0');
    sprintf(sp + 1, "X");

    if (s[12] != 'X')
        abort();
}

int main(void) {
    f();
    exit(0);
}
