#include "bits/stdc++.h"
#define MAXN 100009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x)  cerr<< #x <<" = "<< x<<endl;
using namespace std;

typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
int n;
string s;
ll dp[11][2];
ll DP[11][2];
ll cnt(int pos,int x){
	if(pos==n)
		return 1;
	ll &ret=DP[pos][x];
	if(~ret)
		return ret;ret=0;
	if(pos==n-1){
		for(int i=1;i<=9;i+=2){
			if(!x and s[pos]-'0'<i)
				break;
			ret+=cnt(pos+1,x|(s[pos]-'0'>i));
		}
		return ret;
	}	
	for(int i=0;i<=9;i++){
		if(!x and s[pos]-'0'<i)
			break;
		ret+=cnt(pos+1,x|(s[pos]-'0'>i));
	}
	return ret;
}
ll rec(int pos,int x){
	if(pos==n)
		return 0;
	ll &ret=dp[pos][x];
	if(~ret)
		return ret;ret=0;
	if(pos==n-1){
		for(int i=1;i<=9;i+=2){
			if(!x and s[pos]-'0'<i)
				break;
			ret+=rec(pos+1,x|(s[pos]-'0'>i))+cnt(pos+1,x|(s[pos]-'0'>i))*1LL*i;
		}
		return ret;
	}	
	for(int i=0;i<=9;i++){
		if(!x and s[pos]-'0'<i)
			break;
		ret+=rec(pos+1,x|(s[pos]-'0'>i))+cnt(pos+1,x|(s[pos]-'0'>i))*1LL*i;
	}
	return ret;
}
ll f(int x){s.clear();
	while(x>=1){
		s+=(x%10)+'0';
		x/=10;
	}reverse(all(s));n=s.size();
	memset(dp,-1,sizeof dp);
	memset(DP,-1,sizeof DP);
	return rec(0,0);
}
int main(){
    //~ freopen("file.in", "r", stdin);
    int a,b;
    scanf("%d%d",&a,&b);
    printf("%lld\n",f(b)-f(a-1));
	return 0;
}