#include<iostream>
#include<algorithm>
#include<string.h>
#include<vector>
#include<map>
#include<cassert>
using namespace std;
// #define debug(x) cout<<"[debug]"#x<<"="<<x<<endl
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const ld eps=1e-8;
const int INF=0x3f3f3f3f,mod=998244353;
const ll INFF=0x3f3f3f3f3f3f3f3f;

#ifndef ONLINE_JUDGE
#define debug(...)
#include<debug>
#else
#define debug(...)
#endif

const int N=600005;
vector<int> g[N];
int bel[N];
int len;
vector<int> block[2];
bool dfs(int u, int color=1)
{
    if(bel[u])
        return bel[u]=color;
    bel[u]=color;
    block[color-1].push_back(u);
    for(int v:g[u])
        if(!dfs(v, 3-color))
            return false;
    return true;
}
vector<int> choose;
bool paint() {// 二分图染色
    for(int i=0; i<len; ++i) {
        if(bel[i]) continue;
        block[0].clear();
        block[1].clear();
        if(!dfs(i)) return false;
        if(block[0].size()>block[1].size()) {
            choose.insert(choose.end(),block[0].begin(),block[0].end());
        }else {
            choose.insert(choose.end(),block[1].begin(),block[1].end());
        }
    }
    return true;
}

int main()
{
    int n,m;
    scanf("%d%d",&n,&m);

    vector<pii> all;
    for(int j=1;j<=m;j++) all.push_back({1,j});
    for(int i=2;i<=n;i++) all.push_back({i,m});
    for(int j=m-1;j>=1;j--) all.push_back({n,j});
    for(int i=n-1;i>=2;i--) all.push_back({i,1});

    map<int,int> dig;//对角线
    map<int,int> rdig;//反对角线

    auto add=[&](int x,int y){
        g[x].push_back(y);
        g[y].push_back(x);
    };
    for(int i=0;i<all.size();i++)
    {
        auto [x,y]=all[i];
        if(dig.count(x-y))
        {
            add(dig[x-y],i);
        }
        if(rdig.count(x+y))
        {
            add(rdig[x+y],i);
        }
        dig[x-y]=i;
        rdig[x+y]=i;
    }
    len=all.size();
    assert(paint());
    
    // choose 
    printf("%d\n",choose.size());
    for(auto i:choose)
    {
        auto [x,y]=all[i];
        printf("%d %d\n",x,y);
    }
}