#include <bits/stdc++.h>
using namespace std;
typedef int64_t ll;
typedef vector<string> vss;
struct Solution {
    void solve(std::istream& in, std::ostream& out) {
        ll h, w;
        in >> h >> w;
        vss a(h);
        ll count[26] = {};
        for (int i = 0; i < h; i++) {
            in >> a[i];
            for (int j = 0; j < w; j++) {
                count[a[i][j] - 'a']++;
            }
        }
        ll g1 = 1;
        ll g2 = h / 2 + w / 2;
        ll g4 = (h / 2) * (w / 2);
        if (w % 2 == 0 && h % 2 == 0) {
            while (g4-- > 0) {
                for (int i = 0; i < 26; ++i) {
                    if (count[i] % 4 == 0 && count[i]) {
                        count[i] -= 4;
                        break;
                    }
                }
            }
        }
        else if (w % 2 == 0 || h % 2 == 0) {
            bool flag = false;
            if (h % 2 == 1) {
                g2 = h == 1 ? w : w / 2;
                flag = h == 1;
            }
            else if (w % 2 == 1) {
                g2 = w == 1 ? h : h / 2;
                flag = w == 1;
            }
            while (g2-- > 0) {
                for (int i = 0; i < 26; ++i) {
                    if ((flag && count[i] % 2 == 0 && count[i]) || count[i] % 4 == 2) {
                        count[i] -= 2;
                        break;
                    }
                }
            }
            while (g4-- > 0) {
                for (int i = 0; i < 26; ++i) {
                    if (count[i] % 4 == 0 && count[i]) {
                        count[i] -= 4;
                        break;
                    }
                }
            }
        }
        else {
            bool flag = false;
            if (h == 1) {
                g2 = w;
                flag = h == 1;
            }
            else if (w == 1) {
                g2 = h;
                flag = w == 1;
            }
            while (g1-- > 0) {
                for (int i = 0; i < 26; ++i) {
                    if (count[i] % 4 == 1 || count[i] % 4 == 3) {
                        count[i]--;
                        break;
                    }
                }
            }
            while (g2-- > 0) {
                for (int i = 0; i < 26; ++i) {
                    if ((flag && count[i] % 2 == 0 && count[i]) || count[i] % 4 == 2) {
                        count[i] -= 2;
                        break;
                    }
                }
            }
            while (g4-- > 0) {
                for (int i = 0; i < 26; ++i) {
                    if (count[i] % 4 == 0 && count[i]) {
                        count[i] -= 4;
                        break;
                    }
                }
            }
        }
        ll sum = 0;
        for (int i = 0; i < 26; ++i) {
            sum += count[i];
        }
        out << (sum == 0 ? "Yes" : "No") << '\n';
    }
};
void solve(std::istream& in, std::ostream& out) {
    out << std::setprecision(12);
    Solution solution;
    solution.solve(in, out);
}
#include <fstream>
#include <iostream>
int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    istream& in = cin;
    ostream& out = cout;
    solve(in, out);
    return 0;
}


Measured memory_bytes: 256