// 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;}
#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 u, v, w;
bool operator<(const node &other) const {
return w < other.w;
}
bool operator==(const node &other) const {
return u == other.u && v == other.v && w == other.w;
}
};
vector<vector<node>> e;
int n;
bool directed;
bool weighted = 0;
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{u, v, w});
}
int spfa(int s, vector<int> &dis, vector<int> &pre) {
dis.resize(n, INF);
pre.resize(n, -1);
vector<bool> inq(n, 0);
vector<int> cnt(n, 0);
queue<int> q;
dis[s] = 0, q.push(s), inq[s] = 1;
while (!q.empty()) {
int u = q.front(); q.pop();
inq[u] = 0;
for (auto edge: e[u]) {
int v = edge.v, w = edge.w;
if (dis[u] != INF && dis[v] > dis[u] + w) {
pre[v] = u;
dis[v] = dis[u] + w;
if (!inq[v]) {
q.push(v), inq[v] = 1, ++cnt[v];
if (cnt[v] >= n) return v;
}
}
}
}
return -1;
}
void dijkstra(int s, vector<int> &dis) {
dis.resize(n, INF);
vector<bool> vis(n, 0);
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
dis[s] = 0, pq.push({0, s});
while (!pq.empty()) {
int u = pq.top().second; pq.pop();
if (vis[u]) continue;
vis[u] = 1;
for (auto edge: e[u]) {
int v = edge.v, w = edge.w;
if (dis[v] > dis[u] + w) {
dis[v] = dis[u] + w;
pq.push({dis[v], v});
}
}
}
}
void floyd(vector<vector<int>> &dis) {
dis.resize(n, vector<int>(n, INF));
rep(i, 0, n) dis[i][i] = 0;
rep(u, 0, n) for (auto edge: e[u]) {
int v = edge.v, w = edge.w;
dis[u][v] = min(dis[u][v], w);
}
rep(k, 0, n) rep(i, 0, n) rep(j, 0, n) {
if (dis[i][k] == INF || dis[k][j] == INF) continue;
dis[i][j] = min(dis[i][j], dis[i][k] + dis[k][j]);
}
}
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 ? " -> " : " -- ";
for (auto es: e) for (auto edge: es) if (edge.w != 1) weighted = 1;
for (auto es: e) {
for (auto edge: es) {
if (!directed && edge.u > edge.v) continue;
gf << " " << edge.u << notation << edge.v << (weighted ? " ;\n" : ";\n");
}
}
gf << "}\n";
}
void topo(vector<int> &din, vector<int> &vs) {
queue<int> q;
rep(i, 0, n) if (!din[i]) q.push(i);
vs.clear();
while (!q.empty()) {
int u = q.front(); q.pop();
vs.push_back(u + 1);
for (auto [_, v, __]: e[u]) {
if (!--din[v]) q.push(v);
}
}
}
};
struct STmax {
vector<int> a;
vector<vector<int>> dp;
STmax(vector<int> v) {
a = v;
build();
}
void build() {
int logn = log2(sz(a)) + 2;
dp.assign(sz(a), vector<int>(logn, 0));
rep(i, 0, sz(a)) dp[i][0] = a[i];
rep(j, 1, logn) {
rep(i, 0, sz(a)) {
dp[i][j] = max(dp[i][j-1], dp[min(i + (1 << (j-1)), sz(a)-1)][j-1]);
}
}
}
int query(int l, int r) {
int j = log2(r - l + 1);
return max(dp[l][j], dp[r - (1 << j) + 1][j]);
}
};
int32_t main() {
ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
int n, m; cin >> n >> m;
graph g(n, 1);
vector<int> din(n, 0);
rep(i, 0, m) {
int u, v; cin >> u >> v;
g.add_edge(u-1, v-1);
++din[v-1];
}
g.graphviz_dump();
vector<int> vs;
g.topo(din, vs);
if (sz(vs) != n) cout << "IMPOSSIBLE\n";
else rep(i, 0, n) cout << vs[i] << " \n"[i==n-1];
return 0;
}
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