//No.149 碁石の移動
#pragma GCC optimize("O3")
#pragma GCC target("avx")
#include <bits/stdc++.h>
#define rep(i ,n) for(int i=0;i<(int)(n);++i)

using namespace std;

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

    if( c >= ab ) {
        aw -= ( c - ab);
        bw += ( c - ab);
        if( d >= bw){
            aw += bw;
        } else {
            aw += d;
        }
    } else {
        if( d >= bw ){
            aw += bw;
        } else {
            aw += d;
        }
    }
    cout << aw << endl;  
}