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0_0_23196317_24192.cpp: In function 'int main()':
0_0_23196317_24192.cpp:45:78: error: label 'output' used but not defined
 else if(cross(v,Vector(p[i],o))*cross(v,Vector(p[(i+1)%n],o))==0){ans++;goto output;}  //射到镜子交界处
                                                                              ^