#include <cstdio>

static int (*GoToDungeon)();

static int StepOnDragon() {
    printf("Ups, i've stepped on dragon's tail");
    return -1;
}

void Nevermind() {
	GoToDungeon = StepOnDragon;  
}

int main() {
  GoToDungeon();
  return 0;
}