#include <bits/stdc++.h>

using namespace std;

#define iter(v) v.begin(), v.end()
#define SZ(v) int(v.size())
#define pb emplace_back
#define ff first
#define ss second

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

#ifdef zisk
void debug(){cout << endl;}
template<class T, class ... U>
void debug(T a, U ... b){ cout << a << " ", debug(b...); }
template<class T> void pary(T l, T r){
	while(l != r) cout << *l << " ", l++;
	cout << endl;
}
#else
#define debug(...) void()
#define pary(...) void()
#endif

template<class A, class B>
ostream& operator<<(ostream& o, pair<A, B> p){
	return o << '(' << p.ff << ',' << p.ss << ')';
}

	
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	int n, m;
	cin >> n >> m;
	vector<pii> pnt;
	int sx = 0, sy = 0;
	while (n != m) {
		if (n > m) {
			if (m * 2 == n && m % 2 && m != 1) break;
			for (int i = 0;i < m;i++) pnt.push_back(make_pair(sx, sy+i));
			n -= m;
			sx += m;
		} else {
			if (n * 2 == m && n % 2 && n != 1) break;
			for (int i = 0;i < n;i++) pnt.push_back(make_pair(sx+i, sy));
			m -= n;	
			sy += n;
		}
	}
	if (n == m) {
		if (n == 1) {
			pnt.push_back(make_pair(sx, sy));
		} else {
			for (int i = 0;i < n;i++) pnt.push_back(make_pair(sx+i, sy));
			for (int i = 1;i < n-1;i++) pnt.push_back(make_pair(sx+i, sy+n-1));
		}
	} else {
		if (n > m) {
			for (int i = 0;i < m;i++) pnt.push_back(make_pair(sx, sy+i));
			for (int i = 1;i < m-1;i++) pnt.push_back(make_pair(sx+m-1, sy+i));
			for (int i = 0;i < m;i+=2) {
				pnt.push_back(make_pair(sx + n-1, sy+i));
				pnt.push_back(make_pair(sx + n-2, sy+i));
			}
		} else {
			for (int i = 0;i < n;i++) pnt.push_back(make_pair(sx+i, sy));
			for (int i = 1;i < n-1;i++) pnt.push_back(make_pair(sx+i, sy+n-1));
			for (int i = 0;i < n;i+=2) {
				pnt.push_back(make_pair(sx+i, sy+m-1));
				pnt.push_back(make_pair(sx+i, sy+m-2));
			}
		}
	}

	cout << pnt.size() << "\n";
	for (auto p:pnt) cout << p.ff + 1 << " " << p.ss + 1 << "\n";
}