#danglam228

#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll da, db, dc, dd, de, df, dg, dh, di;
int main() {
    
    cin >> da >> db >> dc >> dd >> de >> df >> dg >> dh >> di;

    ll res = LLONG_MAX;

    for (ll i = 0; i <= 100; ++i) {
        for (ll j = 0; j <= 100; ++j) {
            ll db2 = db + i;
            ll dc2 = dc + j;

            if (db2 > df) {
                ll d2 = (dd + db2 - df - 1) / (db2 - df); 
                ll d1 = max(1LL, de - dc2) * d2; 
                ll d3 = max(0LL, d1 - da); 

                ll d4 = d3 * dg + i * dh + j * di; // cost
                res = min(res, d4);
            }
        }
    }

    cout << res << endl;
    return 0;
}

`color(#5C73B9ff)(H)color(#6B68C0ff)(o)color(#795DC6ff)(r)color(#8852CDff)(i)color(#9646D4ff)(z)color(#A53BDAff)(o)color(#B330E1ff)(n)`

#include <bits/stdc++.h>

using namespace std;

int main() {
  long Ht, At, Dt, Hy, Ay, Dy, h, a, d, res = 1e9;
  cin >> Ht >> At >> Dt >> Hy >> Ay >> Dy >> h >> a >> d;

  for (long i = Dt; i <= 100; ++i)
    for (long j = At; j <= 200; ++j) {
      long t_A = max(j - Dy, 0L);
      if (t_A) {
        long time = (Hy + t_A - 1) / t_A;
        res = min(res, (i - Dt) * d + (j - At) * a + max(time * max(Ay - i, 0L) - Ht + 1, 0L) * h);
      }
    }

  cout << res;
  return 0;
}