#include #include #include using std::cin; using std::cout; const char endl = '\n'; int t; long long l; long long euler(long long x) { long long r = x; for (long long i = 2; i * i <= x; i++) { if (x % i == 0) { r = r / i * (i - 1); while (x % i == 0) x /= i; } } if (x > 1) r = r / x * (x - 1); return r; } long long binmul(long long a, long long b, long long m) { unsigned long long c = (unsigned long long)a * b - (unsigned long long)((long double)a / m * b + 0.5L) * m; if (c < m) return c; return c + m; } long long binpow(long long a, long long b, long long m) { a %= m; long long res = 1; while (b > 0) { if (b & 1) res = binmul(res, a, m); a = binmul(a, a, m); b >>= 1; } return res; } int main() { std::ios::sync_with_stdio(false); while (cin >> l, l) { long long d = std::__gcd(l, 8ll); long long n = euler(9ll * l / d); long long ans = std::numeric_limits::max(); for (long long i = 1; i * i <= n; i++) { if (n % i == 0) { if (binpow(10, i, 9ll * l / d) == 1) ans = std::min(ans, i); if (binpow(10, n / i, 9ll * l / d) == 1) ans = std::min(ans, n / i); } } cout << "Case " << ++t << ": " << (ans == std::numeric_limits::max() ? 0 : ans) << endl; } return 0; }