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

#define ll long long
#define all(x) x.begin(), x.end()
#define pb push_back
#define mp make_pair
#define ps push
#define in insert
#define f first
#define s second
#define nl cout<<"\n"
#define ca(v) for(auto i:v) cout<<i<<" ";
#define cbit(x) __builtin_popcount(x)
#define gcd(a, b) __gcd(a, b)
#define lcm(a, b) (a*b/gcd(a, b))
const int xm[4] = {-1, 1, 0, 0};
const int ym[4] = {0, 0, -1, 1};
const int MOD = 1e9 + 7;
const int MAXN = 5e5 + 5;
const ll POW = 9973;

vector<pair<int, int>> res;
void solve(int x1, int y1, int x2, int y2){
    if(x2 - x1 > y2 - y1){
        for(int y=y1; y<=y2; y++){
            res.pb({x1, y});
        }
        solve(x1 + (y2 - y1 + 1), y1, x2, y2);
    }
    else if(y2 - y1 > x2 - x1){
        for(int x = x1; x<=x2; x++){
            res.pb({x, y1});
        }
        solve(x1, y1 + (x2 - x1 + 1), x2, y2);
    }
    else {
        if(x2 == x1) res.pb({x1,y1});
        else {
            for(int i=x1; i<x2; i++){
                res.pb({i, y1});
                res.pb({i, y2});
            }
        }
    }

}
void out(ll x, ll y, ll swp){
    if(swp) res.pb({y,x});
    else res.pb({x,y});
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    if (fopen("input.in", "r")) {
        freopen("input.in", "r", stdin);
        freopen("output.out", "w", stdout);
    }
    ll n, m;
    cin>>n>>m;
    solve(1, 1, n, m);
    cout<<res.size()<<"\n";
    for(auto p : res) cout<<p.f<<" "<<p.s<<"\n";
}