Language: C++

# include <iostream>
# include <algorithm>
# include <vector>
# include <string>
# include <set>
# include <map>
# include <cmath>
# include <iomanip>
# include <functional>
# include <utility>
# include <stack>
# include <queue>
# include <list>
# include <tuple>
# include <unordered_map>
# include <numeric>
# include <complex>
# include <bitset>
# include <random>
# include <chrono>
# include <cstdlib>
# include <tuple>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
constexpr int INF = 2147483647;
constexpr int HINF = INF / 2;
constexpr double DINF = 100000000000000000.0;
constexpr double HDINF = 50000000000000000.0;
constexpr long long LINF = 9223372036854775807;
constexpr long long HLINF = 4500000000000000000;
const double PI = acos(-1);
template <typename T_char>T_char TL(T_char cX) { return tolower(cX); };
template <typename T_char>T_char TU(T_char cX) { return toupper(cX); };
const int vy[] = { -1, -1, -1, 0, 1, 1, 1, 0 }, vx[] = { -1, 0, 1, 1, 1, 0, -1, -1 };
const int dx[4] = { 0,1,0,-1 }, dy[4] = { 1,0,-1,0 };
# define ALL(x)      (x).begin(),(x).end()
# define UNIQ(c)     (c).erase(unique(ALL((c))),(c).end())
# define LOWER(s)    transform(ALL((maze)),(maze).begin(),TL<char>)
# define UPPER(s)    transform(ALL((maze)),(maze).begin(),TU<char>)
# define FOR(i,a,b)  for(LL i=(a);i<(b);i++)
# define RFOR(i,a,b) for(LL i=(a);i>=(b);i--)
# define REP(i,n)    FOR(i,0,n)
# define INIT        std::ios::sync_with_stdio(false);std::cin.tie(0)

int cnt[30];
string s[15];
int h, w;
int cnta[15][26], cntb[15][26];//a:横の列,b:縦の列
int main() {
	cin >> h >> w;
	REP(i, h)cin >> s[i];
	REP(i, h)REP(j, w) {
		cnt[s[i][j] - 'a']++;
		cnta[i][s[i][j] - 'a']++;
		cntb[j][s[i][j] - 'a']++;
	}
	bool bob = false;
	REP(i, 26) {
		if (cnt[i] % 2 == 1) {
			if (bob) {
				cout << "NO" << endl;
				return 0;
			}
			bob = true;
		}
	}
	bool boo = false;
	int bo1, bo2;
	REP(i, h) {
		int num = 0;
		REP(j, h) {
			if (i == j)continue;
			REP(k, 26) {
				if (cnta[i][k] != cnta[j][k])break;
				if (k == 25)num++;
			}
		}
		if (num % 2 == 0) {
			if (h % 2 == 0) {
				cout << "NO" << endl;
				return 0;
			}
			else {
				if (boo) {
					cout << "NO" << endl;
					return 0;
				}
				boo = true;
				bo1 = i;
			}
		}
	}
	if (h % 2 == 1) {
		if (!boo) {
			cout << "NO" << endl;
			return 0;
		}
	}
	bool boo2 = false;
	REP(i, h) {
		int num = 0;
		REP(j, h) {
			if (i == j)continue;
			REP(k, 26) {
				if (cntb[i][k] != cntb[j][k])break;
				if (k == 25)num++;
			}
		}
		if (num % 2 == 0) {
			if (w % 2 == 0) {
				cout << "NO" << endl;
				return 0;
			}
			else {
				if (boo2) {
					cout << "NO" << endl;
					return 0;
				}
				boo2 = true;
				bo2 = i;
			}
		}
	
		int nummm = 0;
	REP(i, 26) {
		if (cnta[bo1][i] % 2 == 1) {
			if (cntb[bo2][i] % 2 == 0) {
				cout << "NO" << endl;
				return 0;
			}
			else {
				nummm++;
			}
		}
	}
	if (nummm != 1) {
		cout << "NO" << endl;
		return 0;
	}
	if (w % 2 == 1) {
		if (!boo2) {
			cout << "NO" << endl;
			return 0;
		}
	}
	cout << "YES" << endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:148:2: error: expected '}' at end of input
  148 | }
      |  ^
a.cc:50:12: note: to match this '{'
   50 | int main() {
      |            ^