#include <bits/stdc++.h>
#define maxn 100005

using namespace std;

int nxt[maxn], ans[maxn];
int n, m;
void solve() {
    scanf("%d%d", &n, &m);

    for (int i = 1; i <= n; i++) {
        nxt[i] = 0;
    }

    for (int i = 1; i <= m; i++) {
        int l, r;
        scanf("%d%d", &l, &r);
        nxt[l] = max(nxt[l], r);
    }

    for (int i = 1; i <= n; i++) {
        nxt[i] = max(nxt[i - 1], nxt[i]);

        if (nxt[i] < i)
            nxt[i] = i;
    }

    set<int> st;

    for (int i = 1; i <= n; i++) {
        st.insert(i);
    }

    for (int i = 1; i <= n; i++) {
        int now = *st.begin();
        st.erase(now);
        ans[now] = i;

        for (;;) {
            now = nxt[now] + 1;
            set<int> ::iterator it = st.lower_bound(now) ;

            if (it == st.end())
                break;
            else {
                now = *it;
                st.erase(it);
            }

            ans[now] = i;
        }
    }

    for (int i = 1; i <= n; i++) {
        printf("%d ", ans[i]);
    }

    putchar('\n');
}
int main() {
    int T;
    scanf("%d", &T);

    while (T--) {
        solve();
    }
}