#include <cstdio>
#include <cstdint>

int main() {
  int Aw, Ab;
  int Bw, Bb;
  int C, D;
  scanf("%d %d %d %d %d %d", &Aw, &Ab, &Bw, &Bb, &C, &D);

  if (C <= Ab) {
    Ab -= C;
    Bb += C;
  } else {
    Aw -= (C-Ab);
    Bw += (C-Ab);
    Bb += Ab;
    Ab = 0;
  }

  fprintf(stderr, "[%d, %d] [%d, %d]\n", Aw, Ab, Bw, Bb);

  if (D <= Bw) {
    Bw -= D;
    Aw += D;
  } else {
    Bb -= (D-Bw);
    Ab += (D-Bw);
    Aw += Bw;
    Bw = 0;
  }

  fprintf(stderr, "[%d, %d] [%d, %d]\n", Aw, Ab, Bw, Bb);
  printf("%d\n", Aw);
}