#include #include void sb() { uint64_t n = 0; uint64_t ans = 1; scanf("%llu", &n); if (!n) ans = 0; if (n > 49) { printf("000000000000\n"); return; } while (n) { ans *= n--; ans %= 1000000000000; } printf("%llu\n", ans); } void main() { sb(); }