#define Z(i)for(X[i]=X[i-1]+1;X[i]<31;X[i]++)
B[99],V[4],X[4],T=98,R,i,j,r;main(){
    scanf("%d%d%d%d",V,V+1,V+2,V+3);R=T;
    Z(1)Z(2)Z(3){
        for(j=-1;++j<=T;)B[j]=!j;
        for(i=4;--i>0;)for(j=X[i];j<=T;j++)if(B[j-X[i]]&&(!B[j]||B[j]>B[j-X[i]]))B[j]=B[j-X[i]]+1;
        for(i=r=0;i<4&&B[V[i]];)r+=B[V[i++]]-1;
        if(i>3&&R>r)R=r;
    }
    R=!printf("%d\n",R);
}