#include <bits/stdc++.h>
using namespace std;
int d[1000005], x[1000005], y[1000005];
bool res[1000005];
int t[1000005], tmp[1000005];
int main() {
  int n, m;
  scanf("%d %d", &n, &m);
  for (int i = 1; i <= m; i++)
    scanf("%d %d", &x[i], &y[i]), d[x[i]]++, d[y[i]]++;
  for (int i = 1; i <= m; i++) t[i] = i;
  while (1) {
    for (int i = 1; i <= n; i++) tmp[i] = d[i] / 2;
    int ans = 0;
    for (int i = 1; i <= m; i++)
      if (tmp[x[t[i]]] > 0 && tmp[y[t[i]]] > 0)
        tmp[x[t[i]]]--, tmp[y[t[i]]]--;
      else
        res[t[i]] = true, ans++;
    if (ans <= (n + m + 1) / 2) {
      printf("%d\n", ans);
      for (int i = 1; i <= m; i++)
        if (res[i]) printf("%d %d\n", x[i], y[i]);
      return 0;
    }
    memset(res, 0, sizeof(res));
    random_shuffle(t + 1, t + m + 1);
  }
  return 0;
}
