#include "bits/stdc++.h"
using namespace std;
typedef long long ll;

#define rep(i, begin, end) for(int i = begin; i < end; i++)
#define all(x) x.begin(),x.end()
#define sz(x) (int)x.size()
#define sq(x) (x)*(x)

const int N = 112345;
const int inf = 1e9+7;

void solvetask()
{
    ll n, m;
    cin >> n >> m;

    bool flag = n > m;
    if(flag) swap(n,m);

    ll res = ((m-1)/n + 1) *n;
    ll aux = 0;
    if((m-1) % n >= (n/2)+1){
        if(n & 1)
            aux += ((m-1) % n - (n/2)-1) * 2 + 1;
        else
            aux += ((m-1) % n - (n/2)) * 2;
    }
    // cout << res << " AUX " << ((m-1) % n - (n/2)-1) << '\n';
    res += aux;
    cout << res << '\n';
    for(int i = 1; i <= m; i+= n){
        rep(j,1,n+1)
            if(flag) cout << i << " " << j << '\n';
            else cout << j << " " << i << '\n';
    }
    // cout << "OI\n";
    if(aux){
        for(int i = n - ((m-1) % n) + 1; aux; aux--){
            if(flag) cout << m << " " << i << '\n';
            else cout << i << " " << m << '\n';
            i++;
        }

    }

}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int t = 1;
    // cin >> t;
    while (t--)
        solvetask();
        // cout << (solvetask() ? "Yes" : "No") << '\n';
}