Thin Ice

input/code.cpp: In function 'int main()':
input/code.cpp:46:33: warning: left operand of comma operator has no effect [-Wunused-value]
   46 |                 for(int w = u; w>=i, w--){
      |                                ~^~~
input/code.cpp:46:41: error: expected ';' before ')' token
   46 |                 for(int w = u; w>=i, w--){
      |                                         ^
      |                                         ;

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define vo vector
#define pb push_back
#define sz(x) x.size()
#define fi first 
#define se second
typedef long long ll;
typedef pair<int ,int> pii;
typedef vo<int> vi;

#define rep(i, a, b) for(ll i=(a); i<(b); i++)
#define pr(x) cout << #x << " " << x << endl;
ll const inf = LLONG_MAX, mxn = 1e5+4;
int n, m, ans;


signed main(){
    cin.tie(0)->sync_with_stdio(0);
    cin>>n>>m;
    vi arr(m);
    rep(i, 0, m){
        cin>>arr[i];
    }
    
    if(n==1){
        rep(u, 0, m){
            rep(i, u+1, m){
                int carry = 0;
                rep(w, u, i){
                    carry++;
                    if(carry > arr[w]) carry = arr[w];
                    ans = max(ans, carry);
                }
                for(int w = i-1; w>=u; w--){
                    carry++;
                    if(carry > arr[w]) carry = arr[w];
                    ans = max(ans, carry);  
                }
            }

            rep(i, 0, u){
                int carry = 0;
                for(int w = u; w>=i, w--){
                    carry++;
                    if(carry > arr[w]) carry = arr[i];
                    ans = max(ans, carry);
                }
                rep(w, i, u){
                    carry++;
                    if(carry > arr[w]) carry = arr[w];
                    ans = max(ans, carry);  
                }   
            }
        }
    }

    cout << ans;
}


/*
precalc if each square can go home with a specific amt of coins
calc if we can get there with dfs from that square too
*/