#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
typedef long long ll;
#define int ll

const int N = 1e5+10,mo = 1e9+7;
ll n, m, a[N];
struct node{
    ll l, r;
    bool operator < (const node& x){
        if (l != x.l)return l < x.l;
        return r > x.r;
    }
}b[N];
set<ll> st;



inline void solve(){
    cin >> n >> m;
    st.clear();
    for (int i = 1; i <= n; i++)a[i] = 1, st.insert(i);
    for (int i = 1, l, r; i <= m; i++){
        cin >> l >> r;
        b[i] = {l, r};
    }
    ll l = 1, r = 0;
    sort(b + 1, b + 1 + m);
    for (int i = 1; i <= m; i++){
        if (b[i].r <= r)continue;
        while (l < b[i].l)st.insert(a[l]), l++;
        r = max(r, l - 1);
        while (r + 1 <= b[i].r){
            r++;
            a[r] = *st.begin();
            // cerr << r << " " << a[r] << endl;
            st.erase(*st.begin());
        }
    }
    for (int i = 1; i <= n; i++)cout << a[i] << " ";
    cout << endl;
}



signed main(){
    ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
    int WTN666=1;cin>>WTN666;
    while(WTN666--){
        solve();
    }
}