#include<iostream>
#include<cstring>
#include<vector>
#include<set>
#include<limits>
using namespace std;
using LL = long long;

const int maxn = 1e6 + 5, maxm = 2e6 + 5;
template<typename flow_t>
struct MaxFlow{

    const flow_t INF = numeric_limits<flow_t>::max() / 2;

    int h[maxn], e[maxm], ne[maxm], idx;
    flow_t f[maxm];
    int cur[maxn], q[maxn], d[maxn];
    int V, S, T;

    void init(int v, int s, int t){
        for(int i = 0; i <= v; i++) h[i] = -1;
        idx = 0;
        V = v, S = s, T = t;
    }
    
    void add(int a, int b, flow_t c, flow_t d = 0){
        e[idx] = b, f[idx] = c, ne[idx] = h[a], h[a] = idx++;
        e[idx] = a, f[idx] = d, ne[idx] = h[b], h[b] = idx++;
    }
    
    bool bfs(){
        for(int i = 0; i <= V; i++) d[i] = -1;
        int hh = 0, tt = -1;
        q[++tt] = S, d[S] = 0, cur[S] = h[S];
        while(hh <= tt){
            int t = q[hh++];
            for(int i = h[t]; ~i; i = ne[i]){
                int j = e[i];
                if (d[j] == -1 && f[i]){
                    d[j] = d[t] + 1;
                    cur[j] = h[j];
                    if (j == T) return true;
                    q[++tt] = j;
                }
            }
        }
        return false;
    }
    
    flow_t find(int u, flow_t limit){
        if (u == T) return limit;
        flow_t flow = 0;
        // start from cur[u] instead of h[u] <- important
        for(int i = cur[u]; ~i && flow < limit; i = ne[i]){
            int j = e[i];
            cur[u] = i;
            if (d[j] == d[u] + 1 && f[i]){
                flow_t t = find(j, min(f[i], limit - flow));
                if (!t) d[j] = -1;
                else f[i] -= t, f[i ^ 1] += t, flow += t; 
            }
        }
        return flow;
    }
    
    flow_t dinic(){
        flow_t res = 0, flow;
        while(bfs()) while(flow = find(S, INF)) res += flow;
        return res;
    }
};

MaxFlow<int> flow;
int main(){

#ifdef LOCAL
    freopen("data.in", "r", stdin);
    freopen("data.out", "w", stdout);
#endif

    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);

    int n, m;
    cin >> n >> m;
    
    const int cnt = n + m - 1;
    int s = 0, t = 2 * cnt + 1;
    flow.init(2 * cnt + 1, s, t);
    for(int i = 1; i <= cnt; i++){
        flow.add(s, i, 1);
        flow.add(i + cnt, t, 1);
    }

    auto add = [&](int x, int y){
        int l = x + y - 1;
        int r = m - y + 1 + x - 1;
        flow.add(l, r + cnt, 1);
    };

    for(int i = 1; i <= m; i++){
        add(1, i);
        add(n, i);
    }
    for(int i = 2; i <= n - 1; i++){
        add(i, 1);
        add(i, m);
    }
    flow.dinic();

    auto get = [&](int x, int y){
        int s1 = x + 1;
        int s2 = y - m;
        x = (s1 + s2) / 2;
        y = s1 - x;
        return make_pair(x, y);
    };

    vector<pair<int, int> > ans;
    for(int x = 1; x <= cnt; x++){
        for(int i = flow.h[x]; ~i; i = flow.ne[i]){
            int j = flow.e[i];
            if (j > cnt && j <= 2 * cnt && !flow.f[i]){
                ans.push_back(get(x, j - cnt));
            }
        }
    }
    cout << ans.size() << '\n';
    for(auto [x, y] : ans)
        cout << x << ' ' << y << '\n';

}