#include <cstdio>
 
typedef long long i64;
const int MAXN = 1e5;
 
int v[MAXN + 1];
 
int main() {
  int n, k;
  i64 sol;
  FILE *f = fopen("grupuri.in", "r");
  fscanf(f, "%d%d", &k, &n);
  sol = 0;
  for (int i = 0; i < n; ++i) {
    fscanf(f, "%d", &v[i]);
    sol += v[i];
  }
  fclose(f);
  for (--n; n >= 0; --n) {
    if (v[n] <= sol / k) {
      sol /= k;
      break;
    }
    sol -= v[n];
    --k;
  }
  f = fopen("grupuri.out", "w");
  fprintf(f, "%lld\n", sol);
  fclose(f);
  return 0;
}