#include<bits/stdc++.h>
using namespace std;
const int MX = (1<<17);
set < int > S[MX];
int T , n , m;
int arr[MX];
int main(){
    scanf("%d",&T);
    while(T--){
        scanf("%d %d",&n,&m);
        for(int j = 0 ; j <= n ; j++){
            S[j].clear();
            arr[j] = -1;
        }
        while(m--){
            int a , b;
            scanf("%d %d",&a,&b);
            S[a].insert(b);
        }
        int K = S[0].size() , t = 0;
        for(auto pp : S[0])
            arr[pp] = ++t;

        bool sol = 1;
        for(int pos = 1 ; pos <= n && sol ; pos++){
            if(arr[pos] == -1){
                sol = 0;
                break;
            }
            if(S[pos].size() != S[pos-1].size() && S[pos].size() + 1 != S[pos-1].size()){
                sol = 0;
                break;
            }
            int dif1 = 0 , dif2 = 0 , which1 = 0 , which2 = 0;
            for(auto key : S[pos-1]){
                if(S[pos].count(key) == 0){
                    dif1++;
                    which1 = key;
                }
            }
            for(auto key : S[pos]){
                if(S[pos-1].count(key) == 0){
                    dif2++;
                    which2 = key;
                }
            }
            if(dif1 > 1 || dif2 > 1 || which1 != pos){
                sol = 0;
                break;
            }
            if(which2 == 0) continue;
            arr[which2] = arr[pos];
        }
        if(sol == 0){
            puts("-1");
            continue;
        }
        for(int j = 1 ; j <= n ; j++)
            printf("%d ",arr[j]);
        puts("");
    }
}