#include <iostream>
#include <vector>
using namespace std;


vector<pair<int, int>> ans;
void find(int n, int m, int a, int b) {
  while (true) {
    int dx = n - a;
    int dy = m - b;


    if (dx == dy) {
      for (int i = 1; i <= dx; ++i) {
        ans.emplace_back(a + i, b + 1);
      }
      for (int i = 2; i < dx; ++i) {
        ans.emplace_back(a + i, m);
      }
      return;
    }

    if (dx & 1 && dx * 2 == dy) {
      for (int i = 1; i <= dx; ++i) {
        ans.emplace_back(a + i, b + 1);
        ans.emplace_back(a + i, m);
      }

      for (int i = 2; i <= dx; i += 2) {
        ans.emplace_back(a + i, b + dx);
        ans.emplace_back(a + i, b + dx + 1);
      }
      return;
    }

    if (dy & 1 && dy * 2 == dx) {
      for (int i = 1; i <= dy; ++i) {
        ans.emplace_back(a + 1, b + i);
        ans.emplace_back(n, b + i);
      }
      for (int i = 2; i <= dy; i += 2) {
        ans.emplace_back(a + dy, b + i);
        ans.emplace_back(a + dy + 1, b + i);
      }
      return;
    }

    if (dx < dy) {
      for (int i = 1; i <= dx; ++i) {
        ans.emplace_back(a + i, b + 1);
      }
      b += dx;
    } else {
      for (int i = 1; i <= dy; ++i) {
        ans.emplace_back(a + 1, b + i);
      }
      a += dy;
    }
  }
}


int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  find(n, m, 0, 0);
  cout << ans.size() << '\n';
  for (auto &[x, y]: ans) {
    cout << x << ' ' << y << '\n';
  }
}