#include<iostream>
using namespace std;
int main()
{
	int X, R, V;
	cin >> X >> R >> V;
	int N;
	cin >> N;
	int P, S;
	
	for(int i=0; i<N; i++)
	{
		cin >> P >> S;
		if(abs(X - P) <= R)
		{
			if(S <= V) X = P;
			else
			{
				if(X - P > 0) X += 15;
				else X -= 15;
			}
		}
	}
	cout << X << endl;
}