#include <bits/stdc++.h>
using namespace std;

inline void read(int &x){
	static char c; x = 0,c = getchar();
	while (!isdigit(c)) c = getchar();
	while (isdigit(c)) x = x * 10 + c - '0',c = getchar();
}

int n;
int l[100005];
int ans[100005],cnt[100005];
set<int>S;
void solve(){
	int i,q,ql,qr;
	read(n),read(q);
	S.clear();
	for (i = 1; i <= n; ++i) cnt[i] = ans[i] = 0,l[i] = i,S.insert(i);
	while (q--) read(ql),read(qr),l[qr] = min(l[qr],ql);
	for (i = n-1; i ; --i) l[i] = min(l[i],l[i+1]);
	
	ans[1] = 1,++cnt[1]; if (cnt[1] == 1) S.erase(1);
	for (i = 2; i <= n; ++i){
		for (int j = l[i-1]; j < l[i]; ++j){
			--cnt[ans[j]];
			if (cnt[ans[j]] == 0) S.insert(ans[j]);
		}
		ans[i] = *S.begin();
		++cnt[ans[i]],S.erase(ans[i]);
	}
	for (i = 1; i <= n; ++i) cout << ans[i] << (i<n?' ':'\n');
	
}

int main(){
	int T; read(T);
	while (T--) solve(); 
	return 0;
}