E0040.cpp

// Problem Code: TAVISUAL

#include <iostream>
#include <utility>
#include <vector>

using namespace std;

int ballAndCups(int N, int C, vector<pair<int, int>> &queries) {
	int L, R;
	for(int i=0 ; i<queries.size() ; i++){
		L = queries[i].first;
		R = queries[i].second;
		if(C >= L && C <= R)
			C = R - C + L;
	}
	return C;
}

int main() {
	int T, N, C, Q, L, R;
	vector<pair<int, int>> queries;
	cin >> T;
	while(T--){
		cin >> N >> C >> Q;
		for(int i=0 ; i<Q ; i++){
			cin >> L >> R;
			queries.push_back(make_pair(L, R));
		}
		cout << ballAndCups(N, C, queries) << endl;
		queries.clear();
	}
	return 0;
}