#include "bits/stdc++.h"

using namespace std;
using lint = int64_t;

int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n, m;
    cin>>n>>m;
    vector<pair<int, int>>ans;
    auto solve = [&](auto& self, int x, int y, int a, int b, int sw)->void {
        if(x == y){
            for(int i=0;i<x;i++){
                if(sw) ans.emplace_back(b, i+a);
                else ans.emplace_back(i+a, b);
            }
            for(int i=1;i<x-1;i++){
                if(sw) ans.emplace_back(x-1+b, i+a);
                else ans.emplace_back(i+a, x-1+b);
            }
            return;
        }
        if(x > y) swap(x, y), swap(a, b), sw ^= 1;
        for(int i=0;i<x;i++){
            if(sw) ans.emplace_back(b, i+a);
            else ans.emplace_back(i+a, b);
        }
        self(self, x, y-x, a, b + x, sw);
    };
    solve(solve, n, m, 0, 0, 0);
    cout<<ans.size()<<"\n";
    for(auto [a, b] : ans) cout<<a+1<<" "<<b+1<<"\n";

    return 0;
}