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

using ll = long long;
const int N = 1e5 + 5, inf = 0x3fffffff, mod = 998244353;
const long long INF = 0x3fffffffffffffff;
vector<array<int, 3>> ans;
void cal(int x, int y, int n, int m, int op)
{
    if(min(n, m)<=0)return;
    if(m==n){
        for(int i = 1; i <= n; i++){
            ans.push_back({i+x, m+y, op});
        }
        for(int i = 2; i < n; i++){
            ans.push_back({i+x, m+y, op});
        }
        return;
    }
    if(n!=m && min(n, m)%2==1 && max(n, m)%min(n, m)==0) {
        int mn = min(n, m);
        if(n==mn){
            int p = 1;
            while(true){
                for(int i = 1; i <= mn; i++)ans.push_back({i+x, p+y, op});
                p += mn;
                if(p+mn>m){
                    for(int i = 2; i < mn; i++){
                        ans.push_back({i+x, p-1+y, op});
                    }
                    for(int i = 1; i <= mn; i+=2){
                        ans.push_back({i+x, m-1+y, op});
                        ans.push_back({i+x, m+y, op});
                    }
                    break;
                }
            }
        }
        else{
            cal(y, x, m, n, op^1);
        }
        return;
    }
    if(n>m){
        for(int i = 1; i <= m; i++){
            ans.push_back({1+x, i+y, op});
        }
        cal(x+m, y, n-m, m, op);
    }
    else cal(y, x, m, n, op^1);
}
int main() {
    #ifdef stdjudge
        freopen("/home/stdforces/code/contest/in.txt", "r", stdin);
        // freopen("/home/stdforces/code/contest/out.txt", "w", stdout);
    #endif

    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, m;
    cin >> n >> m;
    if(n == 1){
        cout << m << '\n';
        for(int i = 1; i <= m; i++) cout << "1 " << i << '\n';
        return 0;
    }
    if(m == 1){
        cout << n << '\n';
        for(int i = 1; i <= n; i++) cout << i << " 1" << '\n';
        return 0;
    }
    cal(0, 0, n, m, 0);
    cout << ans.size() << '\n';
    for(auto [x, y, op]:ans){
        if(op)swap(x, y);
        cout << x << ' ' << y << '\n';
    }
    return 0;
}