#include <bits/stdc++.h>

using namespace std;

#define fst(t) std::get<0>(t)
#define snd(t) std::get<1>(t)
#define thd(t) std::get<2>(t)
#define unless(p) if(!(p))
#define until(p) while(!(p))

using ll = long long;
using P = std::tuple<int,int>;

const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1};

int main(){
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int Aw, Ab, Bw, Bb, C, D;
    std::cin >> Aw >> Ab >> Bw >> Bb >> C >> D;

    int res = 0;
    for(int i=0;i<=Aw;++i){
        int w = i, b = C - i;
        if(Ab < b){continue;}
        
        res = max(res, Aw - w + min(D, Bw + w));
    }

    std::cout << res << std::endl;
}