#include<bits/stdc++.h>
#define int ll
using namespace std;
#define endl '\n'
typedef long long ll;

signed main()
{
	ios::sync_with_stdio(0);
	cout.tie(0);
	cin.tie(0);
	//freopen("out.txt", "w", stdout);
	int n, m; cin >> n >> m;
	assert(max(n, m) <= 2000 || max(n, m) >=70000);
	bool flag = false;
	if (m > n)
		flag = true;
	if (flag) //m>n
	{
		swap(m, n);

		int x = 0;
		if ((n - 1) % m == 0)x = 0;
		else
		{
			x = ((n - 1) / m + 1) * m + 1;
			x = m - (x - n) * 2;
			x = max(0ll, x);
		}
		cout << ((n - 1) / m + 1)*m + x << endl;


		for (int i = 1; i <= n; i += m)
			for (int k = 1; k <= m; k++)
				cout << k << " " << i << endl;
		if (x)
			for (int i = (m - x) / 2 + 1; i <= (m - x) / 2 + x; i++)
				cout << i << " " << n << endl;
	}
	else//n>=m
	{
		int x = 0;
		if ((n - 1) % m == 0)x = 0;
		else
		{
			x = ((n - 1) / m + 1) * m + 1;
			x = m - (x - n) * 2;
			x = max(0ll, x);
		}
		cout << ((n - 1) / m + 1)*m + x << endl;

		for (int i = 1; i <= n; i += m)
			for (int k = 1; k <= m; k++)
				cout << i << " " << k << endl; //((n-1)/m+1)*m
		if (x)
			for (int i = (m - x) / 2 + 1; i <= (m - x) / 2 + x; i++)
				cout << n << " " << i << endl;
	}
	return 0;
}