#include <cstdio>

const int MAXN = 1e5;

int v[MAXN + 1];

int main() {
  int n, k, 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, "%d\n", sol);
  fclose(f);
  return 0;
}