#include <iostream>
using namespace std;

inline int min(int a, int b) {
	return (a < b) ? a : b;
}

int main() {
    int a, d, dist, minA, minB, min2B;

    while (cin >> a >> d && a != 0) {

		minA = minB = min2B = 100000;

        for (int i = 0; i < a; i++) {
			cin >> dist;
			minA = min(minA, dist);
		}

        for (int i = 0; i < d; i++) {
			cin >> dist;
			if (dist < minB) {
				min2B = minB;
				minB = dist;
			} else {
				min2B = min(min2B, dist);
			}
		}

		cout << ((minA < min2B) ? 'Y' : 'N') << endl;
    }
    return 0;
}