1547 공

#include <stdio.h>
 
int main() {
    int m;
    scanf("%d", &m);
 
    int a, b;
    int arr[4] = { 0,1,0,0 };
    for (int i = 0; i < m; i++) {
        scanf("%d %d", &a, &b);
 
        int tmp = arr[a];
        arr[a] = arr[b];
        arr[b] = tmp;
    }
 
    for (int i = 1; i <= 3; i++) {
        if (arr[i] == 1)
            printf("%d", i);            
    }
}