echilibrat_ab

#include <iostream>
using namespace std;

bool echilibrat(int n)
{
    int cp=0,ci=0;
    while(n)
    {
        if(n%10%2)
            ++ci;
        else
            ++cp;
        n/=10;
    }
    if((ci+cp)%2==0&&ci==cp)
        return true;
    return false;
}

int main()
{
    int a,b;
    cin>>a>>b;
    unsigned long long int s=0;
    for(int i=a;i<=b;++i)
        if(echilibrat(i))
            s+=i;
    cout<<s;
    return 0;
}