#include <vector>
#include <cctype>
#include <cstdio>
#include <cstdint>
#include <algorithm>

using i32 = int32_t;
using i64 = int64_t;

struct FSI
{
	template<typename T>
	FSI& operator>>(T &res)
	{
		res = 0; T f = 1; char ch = getchar();
		while (!isdigit(ch)) { if (ch == '-') f = -1; ch = getchar(); }
		while (isdigit(ch)) { res = res * 10 + (ch - '0') * f; ch = getchar(); }
		return *this;
	}
} read;

int main(void)
{
	//Think tiwce, code once.
	i32 n, m;
	read >> n >> m;
	bool flag = n < m;
	std::vector<std::pair<i32, i32>> res;
	for (i32 i = 1; i <= std::max(n, m); i += std::min(n, m)) {
		for (i32 j = 1; j <= std::min(n, m); ++j) {
			i32 a = i, b = j;
			if (flag) std::swap(a, b);
			res.emplace_back(a, b);
		}
		if (i + std::min(n, m) > std::max(n, m)) {
			i32 gap = std::max(n, m) - i + 1;
			i32 tmp = std::min(n, m) - gap + 1;
			for (i32 j = 1 + tmp; j <= std::min(n, m) - tmp; ++j) {
				i32 a = std::max(n, m), b = j;
				if (flag) std::swap(a, b);
				res.emplace_back(a, b);
			}
		}
	}
	printf("%d\n", res.size());
	for (auto t : res) {
		printf("%d %d\n", t.first, t.second);
	}
	return 0;
}