#include<bits/stdc++.h>
using namespace std ;
typedef long long ll ;
typedef unsigned long long ull ;
typedef pair < int , int > pii ;
typedef vector < int > vi ;
#define fi first
#define se second
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()

const int MAXN = 2e5 + 7 ;

int n , m ; 
vector < pii > v ;


vector < pii > st[ MAXN ] ;

void f ( int par ) {
    for ( int i = 0 ; i <= n + m ; ++ i ) { st[ i ].clear ( ) ; }
    for ( int diff = n - 1 ; diff >= 1 - m ; -- diff ) {
        if ( ( abs ( diff ) % 2 ) != par ) { continue ; }
        int mnx = 1 + diff , mxx = m + diff ;
        if ( mnx < 1 ) { mnx = 1 ; }
        if ( mxx > n ) { mxx = n ; }
        st[ mnx + ( mnx - diff ) ].push_back ( { mxx + ( mxx - diff ) , diff } ) ;
    }
    priority_queue < pii > q ;
    for ( int i = 2 ; i <= n + m ; ++ i ) {
        if ( ( i % 2 ) != par ) { continue ; }
        for ( auto [ y , diff ] : st[ i ] ) { q.push ( { -y , diff } ) ; }
        while ( q.empty ( ) == false ) {
            auto [ x , diff ] = q.top ( ) ;
            x = -x ;
            q.pop ( ) ;
            if ( x < i ) { continue ; }
            int a = ( i + diff ) / 2 , b = i - a ;
            v.push_back ( { a , b } ) ;
            break ;
        }
    }
}

void solve ( ) {
    cin >> n >> m ;
    f ( 0 ) ;
    f ( 1 ) ;
    int sz = v.size ( ) ;
    cout << sz << "\n" ;
    for ( auto [ x , y ] : v ) {
        cout << x << " " << y << "\n" ;
    }
}

int main ( ) {
    ios_base :: sync_with_stdio ( false ) ;
    cin.tie ( NULL ) ;
    int t = 1 ; // cin >> t ;
    while ( t -- ) { solve ( ) ; }
    return 0 ;
}