1 #include<cstdio>
 2 #define F(i,a,b) for(int i=a;i<=b;i++)
 3 typedef long long LL;
 4
 5 const LL M=(1<<20)-1,N=1e5+7,sqr=1e4;
 6 LL K,a,b,ahd,bhd,bt,at,reta,retb,T,S,dt[10][16];
 7 inline LL pow(LL x,LL k){
 8     LL an=1;
 9     while(k){
10         if(k&1)an*=x;
11         k>>=1,x*=x;
12     }
13     return an;
14 }
15 //------------Hash table------------------------
16 struct E{LL key;LL cnt;E *nxt;}*g[M+1],pool[N],*cur=pool,*p;LL vis[M+1];
17 void init_Hash(){T++,cur=pool;}
18 inline void ins(LL key){
19     if(key>S)return;
20     LL u=key&M;
21     if(vis[u]<T)vis[u]=T,g[u]=NULL;
22     for(p=g[u];p;p=p->nxt)if(p->key==key){p->cnt++;return;}
23     p=cur++,p->key=key,p->cnt=1,p->nxt=g[u],g[u]=p;
24 }
25
26 inline LL ask(LL key){
27     if(key<0)return 0;
28     LL u=key&M;
29     if(vis[u]<T)return 0;
30     for(p=g[u];p;p=p->nxt)if(p->key==key)return p->cnt;
31     return 0;
32 }
33 //----------------------------------------------
34 inline LL cal(LL x){
35     LL an=0;
36     while(x)an+=dt[x%10][K],x/=10;
37     return an;
38 }
39 void init(){F(i,0,9)F(j,1,15)dt[i][j]=pow(i,j);}
40 int main(){
41     init();
42     while(~scanf("%lld%lld%lld%lld",&a,&b,&K,&S)){
43         init_Hash();
44         ahd=(a-1)/sqr,bhd=b/sqr,at=(a-1)%sqr,bt=b%sqr;
45         if(at<bt){
46         F(i,0,at)ins(cal(i));
47         reta=ask(S-cal(ahd));
48         F(i,at+1,bt)ins(cal(i));
49         retb=ask(S-cal(bhd));
50         F(i,bt+1,sqr-1)ins(cal(i));
51     }else{
52         F(i,0,bt)ins(cal(i));
53         retb=ask(S-cal(bhd));
54         F(i,bt+1,at)ins(cal(i));
55         reta=ask(S-cal(ahd));
56         F(i,at+1,sqr-1)ins(cal(i));
57     }
58     F(i,ahd,bhd-1)retb+=ask(S-cal(i));
59     printf("%lld\n",retb-reta);
60     }
61     return 0;
62 }