#include<cstdio>#include<cstring>#include<iostream>#include<algorithm>#include<cmath>using namespace std;int ten[20],q[2000100],tail;void gao(int now,int d,int x,int y){if(d>=0&&d<=9){now--;y+=d;}elsereturn;if(now==0){q[tail++]=y;}else{int t=x/ten[now-1];x-=t*ten[now-1];y*=10;gao(now,d-t,x,y);if(t!=0)gao(now,d+t,x,y);}}int coun(int a){if(q[0]>a)return 0;if(q[tail-1]<=a)return tail;int l,r;l=0;r=tail-1;while(r-l>1){int mid=(l+r)>>1;if(q[mid]>a)r=mid;else l=mid;}return l+1;}int main(){int i,len,ans,l,r,ansl,ansr,j,a,b,k,n,m;ten[0]=1;for(i=1;i<10;i++)ten[i]=ten[i-1]*10;q[0]=7;tail=1;for(len=2;len<=9;len++){m=tail;for(i=0;i<m;i++){for(j=1;j<=9;j++)gao(len,j,q[i],0);}}sort(q,q+tail);while(scanf("%d%d",&a,&b)!=EOF){ansl=coun(a-1);ansr=coun(b);ans=ansr-ansl;if(ans<0)ans=0;printf("%dn",ans);}}
