#include <iostream> #include <vector> #include <string> #include <map> #include <set> #include <algorithm> #include <cmath> typedef long long ll; template<typename T> void read_some(std::vector<T> &v, int N) { for (int i = 0; i < N; i++) { T a; std::cin >> a; v.push_back(a); } } template<typename T> void print_some(std::vector<T> &v) { std::cout << "["; for (int i = 0; i < v.size(); i++) { std::cout << " " << v[i]; } std::cout << " ]" << std::endl; } bool dfs(int i, std::vector<int> &x, std::vector<int> *adj, std::vector<bool> &visited) { if (visited[i]) { return false; } visited[i] = true; bool okay = true; for (int j : adj[i]) { if (visited[j] && (x[i] + x[j]) % 2 != 1) { return false; } if (!visited[j]) { x[j] = (x[i] + 1) % 2; okay = dfs(j, x, adj, visited) && okay; } } return okay; } int main() { int n, m; std::cin >> n >> m; std::vector<int> x(n); std::vector<int> adj[101]; for (int i = 0; i < m; i++) { int u, v; std::cin >> u >> v; u--; v--; adj[u].push_back(v); adj[v].push_back(u); } std::vector<bool> visited(n); bool good = true; for (int i = 0; i < n; i++) { if (visited[i]) { continue; } x[i] = 0; if (!dfs(i, x, adj, visited)) { good = false; break; } } if (good) { std::cout << "Yes" << std::endl; } else { std::cout << "No" << std::endl; } return 0; }