// compile: make data
// run: ./data < data.in
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#include <debug/codeforces.h>
#define debug(x...) _debug_print(#x, x);
#define Debug(x...) _debug_print_format(#x, x);
#else
#define debug(x...)
#define Debug(x...)
#endif
template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;}
typedef std::vector<int> VI;
typedef std::vector<std::vector<int>> VII;
typedef std::vector<std::vector<std::vector<int>>> VIII;
#define rep(i,a,b) for(int i=(a);i<(int)(b);++i)
#define sz(v) ((int)(v).size())
#define print(...) print_(__VA_ARGS__);
#define FIND(a, x) ((find(a.begin(),a.end(),(x))!=a.end())?1:0)
#define cmin(x,...) x=min({(x), __VA_ARGS__})
#define cmax(x,...) x=max({(x), __VA_ARGS__})
#define INTMAX (int)(9223372036854775807)
#define INF (int)(1152921504606846976)
#define double long double
#define int long long
#define MAXN 200010
struct graph {
struct node {
int v, w;
bool operator<(const node &other) const {
return w < other.w;
}
bool operator==(const node &other) const {
return v == other.v && w == other.w;
}
};
vector<vector<node>> e;
int n;
bool directed;
graph(int V, bool D = 0) {
n = V;
e.resize(n);
directed = D;
}
void add_edge(int u, int v, int w = 1) {
e[u].push_back(node{v, w});
}
void tarjan_scc(vector<vector<int>> &scc, vector<int> &belong) {
stack<int> s;
vector<int> dfn(n), low(n), instack(n);
int dfncnt;
scc.clear(), belong.resize(n, -1);
function<void(int)> dfs = [&](int u) {
low[u] = dfn[u] = ++dfncnt, s.push(u), instack[u] = 1;
for (auto edge: e[u]) {
int v = edge.v;
if (!dfn[v]) dfs(v), cmin(low[u], low[v]);
else if (instack[v]) cmin(low[u], dfn[v]);
}
if (dfn[u] == low[u]) {
scc.push_back(vector<int>{});
while (s.top() != u) {
belong[s.top()] = sz(scc) - 1;
scc.back().push_back(s.top());
instack[s.top()] = 0, s.pop();
}
belong[s.top()] = sz(scc) - 1;
scc.back().push_back(s.top());
instack[s.top()] = 0, s.pop();
}
};
rep(i, 0, n) if (!~belong[i]) dfs(i);
}
void graphviz_dump(string filename = "graph.dot") {
ofstream gf; gf.open(filename);
gf << (directed ? "digraph" : "graph") << " {\n";
gf << " "; rep(i, 0, n) gf << i << " ;"[i==n-1]; gf << endl;
string notation = directed ? " -> " : " -- ";
bool weighted = 0;
for (auto es: e) for (auto edge: es) if (edge.w != 1) weighted = 1;
rep(u, 0, n) {
for (auto [v, w]: e[u]) {
if (!directed && u > v) continue;
gf << " " << u << notation << v << (weighted ? " ;\n" : ";\n");
}
}
gf << "}\n";
}
};
int32_t main() {
ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
int n, m; cin >> n >> m;
graph g(n, 1);
rep(i, 0, m) {
int u, v; cin >> u >> v; --u, --v;
g.add_edge(u, v);
}
g.graphviz_dump();
vector<vector<int>> scc;
vector<int> belong;
g.tarjan_scc(scc, belong);
if (sz(scc) == 1) {
cout << "YES" << endl;
return 0;
}
cout << "NO" << endl;
int U = scc[0][0], V = scc[1][0];
vector<int> vis(n, 0);
function<void(int)> dfs = [&](int u) {
vis[u] = 1;
for (auto edge: g.e[u]) {
int v = edge.v;
if (vis[v]) continue;
dfs(v);
}
};
if (vis[V]) cout << V+1 << " " << U+1 << endl;
else cout << U+1 << " " << V+1 << endl;
return 0;
}
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