求解

#include<bits/stdc++.h>
using namespace std;
int ball[4]; 
int main(){
 freopen("input.txt","r",stdin);
 freopen("output.txt","w",stdout);
 memset(ball,0,sizeof(ball));
 int k=0,o=0,p=0;
 scanf("%d",&k);
 ball[k]=1;
 for(int i=1;i<=3;i++)
 {
 	cin>>o>>p;
 	swap(ball[o],ball[p]);
 }
 for(int i=1;i<3;i++)
 {
 	if(ball[i]==1)
 	{
 		cout<<i;
 		return 0;
	}
 }

 return 0;
}


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难受

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QAQ