F 求条，样例已过

#include<bits/stdc++.h>
#define int long long
using namespace std;
bool Begin;
int n, m, minnode[1000005], in[1000005], inb[1000005], q[1000005], inq[1000005], head, tail = -1;
vector<int> g[1000005];
void solve(){
    cin >> n >> m;
    for(int i = 1; i <= n; i ++){
        minnode[i] = 2e18;
    }
    for(int i = 1; i <= m; i ++){
        int u, v; cin >> u >> v;
        g[u].push_back(v); in[v] ++; inb[v] ++;
    }
    q[++ tail] = 1; minnode[1] = 1;
    while(head <= tail){
        int u = q[head ++];
        for(int i = 0; i < g[u].size(); i ++){
            int v = g[u][i]; inb[v] --;
            minnode[v] = min(minnode[v], max(v, minnode[u]));
            if(!inb[v]){
                q[++ tail] = v;
            }
        }
    }
    priority_queue<int, vector<int>, greater<int> > q;
    int maxn = 1;
    for(int i = 1; i <= n; i ++){
        maxn = max(maxn, minnode[i]);
        if(!inq[i]) q.push(i); inq[i] = 1;
        while(q.size() && q.top() <= i){
            for(int j = 0; j < g[q.top()].size(); j ++){
                if(!inq[g[q.top()][j]] && g[q.top()][j] > i){
                    q.push(g[q.top()][j]); inq[g[q.top()][j]] = 1;
                }
            }
            inq[q.top()] = 0; q.pop();
        }
        if(maxn > i){
            cout << "-1\n";
        }
        else{
            cout << q.size() << "\n";
        }
    }
}
bool End;
signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int t = 1;
    // cin >> t;
    while(t --){
        solve();
    }
    cerr << "\nMemory Limit: " << abs(&End - &Begin) / 1048576 << "MB"; return 0;
}