//////////给我用long long啊啊啊啊啊啊啊ε＝ε＝ε＝(#>д<)ﾉ
#include<bits/stdc++.h>
using namespace std;
int main()
{
    long long int a = 10;
    long long int l,r;
    //cin >> l >> r;
    scanf("%lld %lld",&l,&r);
    long long int deter = 0;
    if (l == r)
    {
        deter = 1;
        if (r / 10 == 0)
        {
            goto end;
        }
        
    }
    else if(r - l >= 10)
    {
        deter = 2;
        cout << "2";
        goto end;
    }
    else if(l % 10 <= 2&&r % 10 >= 3)
    {
        cout << "2";
        deter = 2;
        goto end;
    }
    else if( (l % 10 < 2&&r % 10 ==2)||(l % 10 == 3&& r % 10 >3) )
    {
        deter = 1;
        if (r / 100 == 0)
        {
            goto end;
        }
    }
    for (a = 10; a <= 1e18; a *= 10)
    {
        if (r / a==0)
        {
            goto end;
        }
        else if( (l/a) %10 <= 2&& (r/a) % 10 >= 3)
        {
            cout << "2";
            deter = 2;
            goto end;
        }
        
    }
end:
    if (deter == 0)
    {
        cout << "1";
    }
    else if (deter == 1)
    {
        cout << deter;
    }
    return 0;
}