#include <iostream>
#include <vector>

int main() {
	int n, m;
	std::cin >> n >> m;

	std::cout << "YES\n";
	std::cout << 2 * m << '\n';
	for (int idx = 0; idx < m; ++idx) {
		int a, b;
		std::cin >> a >> b;

		std::cout << a << ' ' << b << ' ';
		for (int i = 1; i <= n; ++i) {
			if (i == a || i == b) continue;
			std::cout << i << ' ';
		}
		std::cout << '\n';

		for (int i = n; i >= 1; --i) {
			if (i == a || i == b) continue;
			std::cout << i << ' ';
		}
		std::cout << a << ' ' << b << ' ';
		std::cout << '\n';
	}
}