#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rp(i,a,b)        for(int i=a;i<b;i++)

void solvetask(){
    int n, m;
    cin >> n >> m;
    bool flag = false;

    if(n > m){
        swap(n, m);
        flag = true;
    }
    
    vector<pair<int, int>> resp;

    rp(i, 0, n) resp.push_back({1, i+1});
    if(m <= n+1){
        int comp = n+1 - m, t = n - comp*2;
        if(t > 0){
            int d = (n-t)/2;
            rp(i, d, n-d) resp.push_back({m, i+1});
        }
        ll r = resp.size();
        cout << r << "\n";
        for(auto i: resp) if(flag) cout << i.first << " " << i.second << "\n";
        else cout << i.second << " " << i.first << "\n";
        return;
    }

    rp(i, 0, n) resp.push_back({m, i+1});

    if (n % 2 == 0) {
        if(m&1){
            rp(i, n/2 + 1, m - n/2) {
                if ((m-i)% 2 == 0) {
                    resp.push_back({i+1, n/2});
                    resp.push_back({i+1, (n/2)+1});
                }
            }
        }
        else{
            rp(i, n/2 + 1, m - n/2 - 1) {
                if (i% 2 == 0) {
                    resp.push_back({i+1, n/2});
                    resp.push_back({i+1, (n/2)+1});
                }
            }
        }
        
    } else {
        rp(i, (n+1)/2, m - (n+1)/2) {
            resp.push_back({i+1, (n+1)/2});
        }
    }

    ll r = resp.size();
    cout << r << "\n";

    for(auto i: resp) {
        if(flag) cout << i.first << " " << i.second << "\n";
        else cout << i.second << " " << i.first << "\n";
    }
}

int main(){
    cin.tie(0)->sync_with_stdio(0);
    ll t = 1;
    while(t--) solvetask();
}