#include<stdio.h>
FILE*fin,*fout;
unsigned long int s,i,u1,u,u2,u3,tpp,tp,tppp,tcurent,t1,t2,t3,n;
int main(){
fin=fopen("koba.in","r");
fout=fopen("koba.out","w");
fscanf(fin,"%ld %ld %ld %ld",&n,&t1,&t2,&t3);
s=0;
tp=t3;tpp=t2;  tppp=t1;  s=t1%10+t2%10+t3%10;
for(i=4;i<=n;i++){
     tcurent=tp+tpp*tppp;
     u=tcurent%10;
     s=s+u;
     tppp=tpp;tpp=tp; tp=tcurent;

}
fprintf(fout,"%ld",s);
fclose(fin);
fclose(fout);
return 0;
}