#include<iostream>
#include<stdio.h>

using namespace std;

int main(){
    int aw, ab, bw, bb;
    cin>> aw>> ab;
    cin>> bw>> bb;
    int c, d;
    cin>> c>> d;

    int trb = min(ab, c);
    aw = aw - (c-trb);
    bw = bw + (c-trb);
    int trw = min(bw, d);
    aw = aw + trw;

    cout<< aw<< endl;

    return 0;
}