#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<algorithm>
#include<cstring>
#include<queue>
#include<vector>
#include<bitset>
#include<map>
#include<deque>
#include<stack>
using namespace std;
typedef pair<int,int> pii;
#define X first
#define Y second
#define pb push_back
#define mp make_pair
typedef long long ll;
#define ms(a,b) memset(a,b,sizeof(a))
const int inf = 0x3f3f3f3f;
const int maxn = 1e6;
const int mod = 1e9+7;#define lson l,m,2*rt
#define rson m+1,r,2*rt+1
int dp[10][3];void init(){dp[0][0]=1;dp[0][1]=dp[0][2]=0;for(int i=1;i<7;i++){dp[i][0]=9*dp[i-1][0]-dp[i-1][1]; //在最高位加上除4以外的9个数字，但要减掉2之前加上6dp[i][1]=dp[i-1][0]; //在不含不吉利数字的最高位加上2dp[i][2]=dp[i-1][0]+dp[i-1][1]+10*dp[i-1][2];　　　　　//在已有不吉利数字前加任意数字，或者无不吉利数字的最高位加4，或者在2前面加6}
}
int bit[10];int solve(int x){int t=x;int len=0;while(t){bit[++len]=t%10;t/=10;}bit[len+1]=0;int ans=0;bool flag=false;for(int i=len;i>=1;i--){ans += dp[i-1][2]*bit[i];if(flag) ans+=dp[i-1][0]*bit[i]; //高位已经出现4或者62，后面随意else{if(bit[i]>4) ans+=dp[i-1][0]; if(bit[i+1]==6&&bit[i]>2) ans+=dp[i][1];if(bit[i]>6) ans+=dp[i-1][1];}if(bit[i]==4 || (bit[i+1]==6&&bit[i]==2)) flag=true;}if(flag) ans++;return x-ans;
}
int main(){
#ifdef LOCALfreopen("in.txt","r",stdin);
#endif // LOCALint l,r;init();while(scanf("%d%d",&l,&r)&&(l||r)){printf("%d\n",solve(r)-solve(l-1));}return 0;
}

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<algorithm>
#include<cstring>
#include<queue>
#include<vector>
#include<bitset>
#include<map>
#include<deque>
#include<stack>
using namespace std;
typedef pair<int,int> pii;
#define X first
#define Y second
#define pb push_back
#define mp make_pair
typedef long long ll;
#define ms(a,b) memset(a,b,sizeof(a))
const int inf = 0x3f3f3f3f;
const int maxn = 1e6;
const int mod = 1e9+7;#define lson l,m,2*rt
#define rson m+1,r,2*rt+1
int dp[maxn+5];void init(){dp[0]=0;for(int i=1;i<maxn;i++){dp[i]=dp[i-1];bool f=0;int pre=0;int x=i;while(x){if(x%10==4){f=1;break;}else if(pre==2&&x%10==6){f=1;break;}pre=x%10;x/=10;}if(f){dp[i]++;}}
}int main(){
#ifdef LOCALfreopen("in.txt","r",stdin);
#endif // LOCALint l,r;init();while(scanf("%d%d",&l,&r)&&(l||r)){printf("%d\n",r-l+1-(dp[r]-dp[l-1]));}return 0;
}