#include<iostream>
#include<string>
#include<cmath>

bool check(std::string n){
        char wave[2];
        wave[0]=n[0];
        wave[1]=n[1];
        for(std::string::size_type i=2;i<n.size();++i)
                if(n[i]!=wave[i%2])
                        return false;
        return true;
}

long log_(long m,long n){//base: m
        return std::log(n)/std::log(m);
}

std::string transfer(long raw,long decimal){
        if(decimal==10)
                return std::to_string(raw);
        else{
                std::string res{};
                long tmp{raw};
                long exp,lstexp{0};
                while((exp=log_(decimal,tmp))!=0){
                        if(lstexp==exp and lstexp!=0){
                                res.back()+=1;
                        }
                        else{
                                for(long i=0;i<lstexp-exp-1;++i)
                                        res.push_back('0');
                                res.push_back('1');
                        }
                        tmp-=std::pow(decimal,exp);
                        lstexp=exp;
                        if(tmp==0)
                                return res;
                }
                for(long i=0;i<lstexp-exp-1;++i)
                        res.push_back('0');
                res.push_back(tmp+'0');
                return res;
        }
}

long l,r,L,R,k;

int main(){
        std::cin>>l>>r>>L>>R>>k;
        for(long i=L;i<=R;++i){
                if(not check(transfer(i,10)))continue;
                long cnt{};
                for(long dec=l;dec<=r and cnt<k;++dec){
                        if(check(transfer(i,dec))){
                                ++cnt;
                        }
                }
                if(cnt==k)
                        std::cout<<i<<std::endl;
        }

        return 0;
}

orz