#include <stdio.h>

int main(){
    int AW, AB, BW, BB, C, D, tmp;

    scanf("%d %d\n%d %d\n%d %d", &AW, &AB, &BW, &BB, &C, &D);

    if(C <= AB){
        AB -= C;
        BB += C;
        //printf("AW: %d AB: %d BW: %d BB: %d\n", AW, AB, BW, BB);
    }else{
        tmp = AB;
        AB = 0;
        AW -= C - tmp;
        BB += tmp;
        BW += C - tmp;
        //printf("AW: %d AB: %d BW: %d BB: %d\n", AW, AB, BW, BB);
    }
    if(D <= BW){
        BW -= D;
        AW += D;
        //printf("AW: %d AB: %d BW: %d BB: %d\n", AW, AB, BW, BB);
    }else{
        tmp = BW;
        BW = 0;
        BB -= D - tmp;
        AW += tmp;
        BB += D - tmp;
        //printf("AW: %d AB: %d BW: %d BB: %d\n", AW, AB, BW, BB);
    }

    printf("%d\n", AW);

    return 0;

}