#include <iostream>

using namespace std;
int a,b,i;
long long sum_a,sum_b;
long long sumt(int n)
{
    long long soli=0;
    for(i=1;i<10;++i)
    {
        long long k=n;
        long long p=1;
        long long sol=0;
        while(k)
        {
            if(k%10>i) sol=sol+(k/10+1)*p;
            if(k%10<i) sol=sol+(k/10)*p;
            if(k%10==i) sol=sol+(k/10)*p+n%p+1;
            k/=10;
            p*=10;
        }
        soli+=1LL*sol*i;
    }
    return soli;
}
int main()
{
    cin>>a>>b;
    --a;
    sum_a=sumt(a);
    sum_b=sumt(b);
    for(i=a;i%10>0;--i)
    {
        int k=i;
        while(k) sum_a-=k%10,k/=10;
    }
    int k=i;
    while(k) sum_a-=k%10,k/=10;
    for(i=b;i%10>0;--i)
    {
        int k=i;
        while(k) sum_b-=k%10,k/=10;
    }
    k=i;
    while(k) sum_b-=k%10,k/=10;
    sum_a-=1LL*(a/10)*45;
    sum_b-=1LL*(b/10)*45;
    sum_a/=2;
    sum_b/=2;
    sum_a+=1LL*(a/10)*25;
    sum_b+=1LL*(b/10)*25;
    for(i=a;i%10>0;--i)
    if(i&1)
    {
        int k=i;
        while(k) sum_a+=k%10,k/=10;
    }
    for(i=b;i%10>0;--i)
    if(i&1)
    {
        int k=i;
        while(k) sum_b+=k%10,k/=10;
    }
    cout<<sum_b-sum_a;
    return 0;
}