#include <cstdio>
#include <algorithm>
#include <cstring>
#define nmax 1000000
using namespace std;
long long s,v[nmax+10],t[nmax/10];

long long sum(int a)
{
    int i,j,k;
    for (i=1;i<=min(nmax-1,a);i+=2)
        v[i]=1;
    memset(t,0,sizeof(t));
    for (i=1;i<nmax;i+=2) {
        k=0;
        for (j=1<<10;j;j>>=1)
            if ((k+j)*1000000+i<=a)
                k+=j;
        v[i]+=k;
        t[k]++;
    }
    for (i=10000;i>=1;i--)
        t[i]+=t[i+1];
    for (i=1;i<=10000;i++) {
        j=i;
        while (j) {
            v[j%10]+=t[i];
            j/=10;
        }
    }
    for (i=nmax-1;i>=10;i--) {
        v[i%10]+=v[i];
        v[i/10]+=v[i];
        v[i]=0;
    }
    s=0;
    for (i=9;i>=1;i--) {
        s+=v[i]*i;
        v[i]=0;
    }
    return s;
}
int main()
{
   // freopen("date.in","r",stdin);
    int i,j,a,b;
    scanf("%d %d",&a,&b);/*
    for (i=a;i<=b;i++)
        if (i%2==1) {
            j=i;
            while (j) {
                s+=j%10;
                j/=10;
            }
        }*/
    //printf("%lld\n",s);
    printf("%lld\n",sum(b)-sum(a-1));

    return 0;
}