AOJ Volume20-2001

http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=2001

#include <iostream>
#include <vector>
using namespace std;

int main (int argc, char * const argv[]) {
    // insert code here...	
	int n;
	
	while (cin >> n) {
		
		if (n == 0) {
			break;
		}
		
		//入力
		int m,a;
		cin >> m;
		cin >> a;
		
		int h[m],p[m],q[m];
		
		for (int i=0; i < m; i++) {
			cin >> h[i];
			cin >> p[i];
			cin >> q[i];
		}
		
		
		//計算
		for (int i=1000; i > 0; i--) {
			for (int j=0; j < m; j++) {
				if (h[j] == i) {
					if (a == p[j]) {
						a = q[j];
						break;
					}else if (a == q[j]) {
						a = p[j];
						break;
					}
				}
			}
		}
		
		cout << a << endl;
		
		
	}
		
    return 0;
}