#include <stdio.h>
#include <string.h>
#include <algorithm>

const int MAXN = 100010;
int T, n, m, maxr, a[MAXN];
bool book[MAXN];

struct seg{
    int l, r;
};
seg p[MAXN];

bool operator < (seg x, seg y) {
    return x.l == y.l ? x.r > y.r : x.l < y.l;
}

int main() {
    // freopen("k.in", "r", stdin);
    // freopen("k.out", "w", stdout);
    scanf("%d", &T);
    while (T--) {
        scanf("%d%d", &n, &m);
        for (int i = 1; i <= n; ++i) a[i] = 0;
        for (int i = 1; i <= m; ++i) {
            scanf("%d%d", &p[i].l, &p[i].r);
        }
        std::sort(p + 1, p + m + 1);
        maxr = 0;
        for (int i = 1; i <= m; ++i) {
            if (p[i].r <= maxr) continue;
            if (p[i].l > maxr) {
                for (int j = 1, pos = p[i].l; pos <= p[i].r; ++j, ++pos) {
                    a[pos] = j;
                }
            } else {
                for (int j = 1; j <= (p[i].r - p[i].l + 1) + (maxr - p[i].l + 1); ++j) {
                    book[j] = false;
                }
                for (int pos = p[i].l; pos <= maxr; ++pos) {
                    book[a[pos]] = true;
                }
                for (int j = 1, pos = maxr + 1; pos <= p[i].r; ++j) {
                    if (book[j]) continue;
                    a[pos] = j;
                    book[j] = true;
                    pos++;
                }
            }
            maxr = std::max(maxr, p[i].r);
        }
        for (int i = 1; i <= n; ++i) {
            printf("%d", a[i] == 0 ? 1 : a[i]);
            if (i < n) printf(" ");
            else printf("\n");
        }
    }
    return 0;
}