#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 800005;

struct node{
    int r,xy;
    bool operator < (const node &nd)const{
        return nd.r < r;
    }
};

int n,m;
vector <pair <int,int> > ans;
vector <node> G[N];

void solve(){
    cin >> n >> m;
    int N = (n + m + 1) / 2 * 2;
    for(int i = 2;i <= N;i += 2){ // x + y = i
        int l = max(i - 2 * m,2 - i);
        int r = min(2 * n - i,i - 2);
        G[l + N].push_back({r + N,i});
    }
    priority_queue <node> q;
    for(int i = 2;i <= N + N;i += 2){
        for(auto nd : G[i]) q.push(nd);
        while(!q.empty() && q.top().r < i) q.pop();
        if(!q.empty()){
            int xy = q.top().xy,yx = i - N; q.pop();
            ans.push_back({(xy + yx) / 2,(xy - yx) / 2});
        }
    }
    for(int i = 3;i <= N;i += 2){ // x + y = i
        int l = max(i - 2 * m,2 - i);
        int r = min(2 * n - i,i - 2);
        G[l + N].push_back({r + N,i});
    }
    while(!q.empty()) q.pop();
    for(int i = 3;i <= N + N;i += 2){
        for(auto nd : G[i]) q.push(nd);
        while(!q.empty() && q.top().r < i) q.pop();
        if(!q.empty()){
            int xy = q.top().xy,yx = i - N; q.pop();
            ans.push_back({(xy + yx) / 2,(xy - yx) / 2});
        }
    }
    cout << ans.size() << '\n';
    for(auto [x,y] : ans) cout << x << ' ' << y << '\n';
}

int main(){
    ios::sync_with_stdio(false);
    solve();
    return 0;
}