#include <bits/stdc++.h>
using namespace std;
int n;
vector<vector<int>> graph;
vector<vector<int>> en_graph;
vector<bool> visited;
vector<int> degs;
void dfs(int u, vector<bool> &conn) {
  visited[u] = true;
  conn[u] = true;
  for (int v = 0; v < n; ++v) {
    if (graph[u][v] != 0 and not visited[v]) {
      dfs(v, conn);
    }
  }
}
void loop(int u, vector<int> &p) {
  for (int v = 0; v < n; ++v) {
    if (en_graph[u][v] != 0) {
      --en_graph[u][v];
      --en_graph[v][u];
      loop(v, p);
    }
  }
  p.push_back(u);
}
void euler(int u, vector<bool> &conn) {
  for (int i = 0, v = -1; i < n; ++i) {
    if (conn[i] and degs[i] % 2 == 1) {
      if (v == -1) {
        v = i;
      } else {
        ++en_graph[v][i];
        ++en_graph[i][v];
        v = -1;
      }
    }
  }
  vector<int> p;
  loop(u, p);
  if (p.size() > 2) {
    for (int i = 0; i < p.size() - 1; ++i) {
      if (graph[p[i]][p[i + 1]]) {
        graph[p[i + 1]][p[i]] = 0;
      }
    }
  }
}
void solve() {
  visited.assign(n, false);
  en_graph = graph;
  vector<bool> conn(n, false);
  for (int u = 0; u < n; ++u) {
    if (not visited[u]) {
      fill_n(begin(conn), n, false);
      dfs(u, conn);
      euler(u, conn);
    }
  }
  for (int u = 0; u < n; ++u) {
    for (int v = 0; v < n; ++v) {
      if (graph[u][v]) {
        cout << u + 1 << " " << v + 1 << "\n";
      }
    }
  }
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  while (true) {
    int t;
    cin >> t;
    if (!cin) {
      break;
    }
    for (int i = 0; i < t; ++i) {
      int m;
      cin >> n >> m;
      graph.assign(n, vector<int>(n, 0));
      degs.assign(n, 0);
      for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        --u;
        --v;
        graph[u][v] = 1;
        graph[v][u] = 1;
        ++degs[u];
        ++degs[v];
      }
      int cnt = n;
      for (int i = 0; i < n; ++i) {
        if (degs[i] % 2 == 1) {
          --cnt;
        }
      }
      cout << cnt << "\n";
      solve();
    }
  }
  return 0;
}
