#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;

int main() {
    #ifdef stdjudge
        freopen("/home/stdforces/code/contest/in.txt", "r", stdin);
    #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;
    }
    if(n!=m && min(n, m)%2==1 && max(n, m)%min(n, m)==0) {
        cout << n+m-1 << '\n';
        int mn = min(n, m);
        if(n==mn){
            int p = 1;
            while(true){
                for(int i = 1; i <= mn; i++)cout << i << ' ' << p << '\n';
                p += mn;
                if(p+mn>m){
                    for(int i = 2; i < mn; i++){
                        cout << i << " " << p-1 << '\n';
                    }
                    for(int i = 1; i <= mn; i+=2){
                        cout << i << " " << m-1 << '\n';
                        cout << i << " " << m << '\n';
                    }
                    break;
                }
            }
        }
        else{
            swap(n, m);
            int p = 1;
            while(true){
                for(int i = 1; i <= mn; i++)cout << p << ' ' << i << '\n';
                p += mn;
                if(p+mn>m){
                    for(int i = 2; i < mn; i++){
                        cout << p-1 << " " << i << '\n';
                    }
                    for(int i = 1; i <= mn; i+=2){
                        cout << m-1 << " " << i << '\n';
                        cout << m << " " << i << '\n';
                    }
                    break;
                }
            }
        }
        return 0;
    }
    int a = n, b = m, s = 0, ans = 0;
    while(a > 0){
        if(a == b) s += b + (b - 2);
        else s += b;
        a -= b;
    }
    ans = s;
    a = m, b = n, s = 0;
    while(a > 0){
        if(a == b) s += b + (b - 2);
        else s += b;
        a -= b;
    }
    if(s <= ans){
        int p = 1;
        cout << ans << '\n';
        int mx = n;
        while(n > 0){
            for(int i = 1; i <= m; i++) cout << p << ' ' <<  i << '\n';
            if(n == m){
                for(int i = 2; i < m; i++) cout << mx << " " << i << '\n';
            }
            p += m;
            n -= m;
        }
    }else{
        int p = 1;
        swap(n, m);
        cout << s << '\n';
        int mx = n;
        while(n > 0){
            for(int i = 1; i <= m; i++) cout << i << ' ' <<  p << '\n';
            if(n == m){
                for(int i = 2; i < m; i++) cout << i << " " << mx << '\n';
            }
            p += m;
            n -= m;
        }
    }
    return 0;
}