/**************************************************************

     Problem: 3427

     User: rausen

     Language: C++

     Result: Accepted

     Time:808 ms

     Memory:16432 kb

 ****************************************************************/

 #include <cstdio>

 #include <cstring>

 #include <algorithm>

 using namespace std;

 const int N = ;

 const int inf = 1e9;

 int a[N], f[N][];

 int n, ans = inf;

 inline int read() {

     int x = , sgn = ;

     char ch = getchar();

     while (ch < '' || '' < ch) {

         if (ch == '-') sgn = -;

         ch = getchar();

     }

     while ('' <= ch && ch <= '') {

         x = x *  + ch - '';

         ch = getchar();

     }

     return sgn * x;

 }

 int main() {

     int i, j, k;

     int t, to;

     n = read();

     for (i = ; i <= n; ++i)

         a[i] = read();

     memset(f, , sizeof(f));

     f[][a[] + ] = ;

     for (i = ; i < n; ++i)

         for (j = ; j <= ; ++j) if (f[i][j] < inf)

             for (t = j - , k = ; k <= ; ++k) {

                 to = a[i + ] + k * t;

                 if (to >= - && to <=  && to >= t)

                     f[i + ][to + ] = min(f[i + ][to + ], f[i][j] + k);

             }

     for (i = ; i <= ; ++i)

         ans = min(ans, f[n][i]);

     if (ans == inf) puts("BRAK");

     else printf("%d\n", ans);

     return ;

 }