#include <iostream>
using namespace std;

int main(int argc, const char * argv[]) {
    
    int Aw,Ab,Bw,Bb,C,D;
    
    cin >> Aw >> Ab;
    cin >> Bw >> Bb;
    cin >> C >> D;

    if(C <= Ab){
        Ab-=C;
        Bb+=C;
    }
    else{
        Aw -= C-Ab;
        Bb += Ab;
        Bw += C-Ab;
    }
    
    if (D <= Bw) {
        Aw += D;
    }
    else{
        Aw += Bw;
    }

    
    cout << Aw << endl;
    
    return 0;
}