#include <bits/stdc++.h>
using namespace std;

int main() {
	int n, m; cin >> n >> m;
	bool flip = false;
	if (n > m) swap(n, m), flip =true;

	vector<array<int,2>> print;

	int i = 0, j = m-1;
	while (j - i >= n) {
		for (int k = 0; k < n; k++) {
			print.push_back({k, i});
			print.push_back({k, j});
		}
		i += n;
		j -= n;
	}

	if (i == j) {
		for (int k = 0; k < n; k++) {
			print.push_back({k, i});
		}
	} else if (i < j) {
		for (int k = 0; k < n; k++) {
			print.push_back({k, i});
		}
		i += n;

		if (j == m-1) {
			int d = m-1;
			int temp = max(0, n - 2*(n-d));
			for (int k = (n-temp)/2; k < (n+temp)/2; k++) {
				print.push_back({k, j});
			}
		} else {
			goto label;
		}
	} else {
label:
		int mid = (i+j)/2;
		int d = min(mid - i + n, j + n - mid);

		int temp = max(0, n - 2 * (n - d));
		for (int k = (n-temp)/2; k < (n+temp)/2; k++) {
			print.push_back({k, mid});
		}
		if ((i+j) % 2 && n % 2) {
			if (temp > 0) {
				mid++;
				while (temp > 1)
					mid++, temp-=2;
				print.push_back({n/2, mid});
			}
		}
	}

	cout << print.size() << '\n';
	for (auto [i,j] : print) {
		if (!flip)
			cout << i+1 << ' ' << j+1 << '\n';
		else
			cout << j+1 << ' ' << i+1 << '\n';
	}
}