#include <stdio.h>

void ToH ( int n, char from, char to, char help )
{
    if (n == 1) {
        printf("Disk %d: %c -> %c\n", n, from, to);
        return;
    }
    ToH(n-1,from,help,to);
    printf("Disk %d: %c -> %c\n", n, from, to);
    ToH(n-1,help,to,from);
}

int main ()
{
    int n;

    printf("n = "); scanf("%d", &n);
    ToH(n,'A','B','C');

    return 0;
}