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

vector<pair<int,int>> sol;
int n,m;

void check(int n,bool flg){
    if(n==0)return;
    
    bool tolto=false;
    if(n%2==0)n--,tolto=true;
    
    for(int i=1;i<=n;i+=2){
        sol.push_back({i+flg,1});
    }
    
    for(int i=1+(m%2==0);i<=n;i+=2){
        if((i!=1 && i!=n) || n!=m){
            sol.push_back({i+flg,m});
        }
    }
    
    int tmp = (n+1)/2;
    if(n%4==1){
        int last = (m%2==1 ? m-tmp+1 : m-tmp+1+1);
        
        if(m%2==0){
            if(flg){
                sol.push_back({1,m});
                last=min(last,m-tmp);
            }
            
            if(tolto){
                sol.push_back({n+1,m});
                last=min(last,m-tmp);
            }
        }
        
        for(int i=tmp+2;i<last;i+=2){
            sol.push_back({tmp+flg,i});
        }
    }else{
        
        int last = (m%2==1 ? m-tmp+1 : m-tmp+1+1);
        
        if(m%2==0){
            if(flg){
                sol.push_back({1,m});
                last=min(last,m-tmp);
            }
            
            if(tolto){
                sol.push_back({n+1,m});
                last=min(last,m-tmp);
            }
        }
        
        for(int i=tmp+2;i<last;i+=2){
            sol.push_back({tmp+flg,i});
        }
    }
}

void solve(int t){
    cin>>n>>m;
    
    bool inv = false;
    
    if(n>m){
        swap(n,m);
        inv=true;
    }
    
    check(n,false);
    check(n-1,true);
    
    assert(sol.size()==n+m-1 || n==m);
    
    cout<<sol.size()<<"\n";
    for(auto [x,y] : sol){
        if(inv)swap(x,y);
        cout<<x<<" "<<y<<"\n";
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int t=1;
    //cin>>t;
    for(int i=1;i<=t;i++)solve(i);
    
    return 0;
}