#include <bits/stdc++.h>

using namespace std;

#define pb push_back

#define fi first

#define se second

#define debug(x) cerr<<#x << " := " << x << endl;

#define bug cerr<<"-----------------------"<<endl;

#define FOR(a, b, c) for(int a = b; a <= c; ++ a)

typedef long long ll;

typedef long double ld;

typedef pair<int, int> pii;

typedef pair<ll, ll> pll;

template<class T> void _R(T &x) { cin >> x; }

void _R(int &x) { scanf("%d", &x); }

void _R(ll &x) { scanf("%lld", &x); }

void _R(double &x) { scanf("%lf", &x); }

void _R(char &x) { scanf(" %c", &x); }

void _R(char *x) { scanf("%s", x); }

void R() {}

template<class T, class... U> void R(T &head, U &... tail) { _R(head); R(tail...); }

template<typename T>

inline T read(T&x){

    x=;int f=;char ch=getchar();

    while (ch<''||ch>'') f|=(ch=='-'),ch=getchar();

    while (ch>=''&&ch<='') x=x*+ch-'',ch=getchar();

    return x=f?-x:x;

}

const int inf = 0x3f3f3f3f;

const int mod = 1e9+;

/**********showtime************/

            const int maxn = 1e5+;

            vector<pii>mp[maxn];

            set   <pii>nmp[maxn];

            int dfn[maxn],low[maxn],belong[maxn],tim;

            int scc_cnt;

            int ans[maxn];

            int a[maxn], dp[maxn];

            stack<int>st;

            void dfs(int u, int fa) {

                dfn[u] = low[u] = ++tim;

                st.push(u);

                for(pii p : mp[u]){

                    int v = p.fi;

                    if(v == fa) continue;

                    if(!dfn[v]) dfs(v, u);

                    if(!belong[v]) low[u] = min(low[u], low[v]);

                }

                if(low[u] == dfn[u]) {

                    scc_cnt++;

                    nmp[scc_cnt].clear();

                    int now;

                    while(true){

                        now = st.top(); st.pop();

                        belong[now] = scc_cnt;

                        a[scc_cnt] = max(a[scc_cnt], now);

                        if(now == u) break;

                    }

                }

            }

            void cal(int u, int fa) {

                dp[u] = a[u];

                for(pii p : nmp[u]) {

                    int v = p.fi, id = p.se;

                    if(v == fa) continue;

                    cal(v, u);

                    ans[id] = dp[v];

                    dp[u] = max(dp[u], dp[v]);

                }

            }

int main(){

            int T;  scanf("%d", &T);

            while(T--) {

                int n,m;

                scanf("%d%d", &n, &m);

                for(int i=; i<=n; i++) mp[i].clear(), dfn[i] = ,dp[i] = , a[i] = ,belong[i] = ;

                for(int i=; i<=m; i++) {

                    int u,v;

                    scanf("%d%d", &u, &v);

                    mp[u].pb(pii(v, i));

                    mp[v].pb(pii(u, i));

                    ans[i] = ;

                }

                tim = ;

                scc_cnt = ;

                for(int i=; i<=n; i++) if(!dfn[i]) dfs(i, i);

                for(int u=; u<=n; u++) {

                    for(pii p : mp[u]) {

                        int v = p.fi;

                        if(belong[u] == belong[v]) continue;

                        nmp[belong[u]].insert(pii(belong[v], p.se));

                    }

                }

                cal(belong[n], belong[n]);

                for(int i=; i<=m; i++) printf("%d %d\n", ans[i], ans[i] + (ans[i] != ));

            }

            return ;

}