Prva

#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
using ii=long long;
int main()
{
    int n, m;
    cin >> n >> m;
    vector<string> v(n);
    for (int i = 0; i < n; ++i) {
        cin >> v[i];
    }
    string res = "zz";
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            if (i == 0 || v[i - 1][j] == '#') {
                string s;
                for (int it = i; it < n; ++it) {
                    if (v[it][j] == '#') break;
                    s.push_back(v[it][j]);
                }
                if (s.size() >= 2) res = min(res, s);
            }
            if (j == 0 || v[i][j - 1] == '#') {
                string s;
                for (int jt = j; jt < m; ++jt) {
                    if (v[i][jt] == '#') break;
                    s.push_back(v[i][jt]);
                }
                if (s.size() >= 2) res = min(res, s);
            }
        }
    }
    cout << res << "\n";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED