1547번: 공

#include<cstdio>

#define swap(a,b) {int t;t=a;a=b;b=t;}

int main()

{

bool b[4] = { 0, 1, 0, 0 }; int m, one, two;

for (scanf("%d", &m); m--;)

{

scanf("%d %d", &one, &two);

swap(b[one], b[two]);

}

for (int i = 1; i < 4; ++i)

if (b[i] == 1) printf("%d", i);

}