#include <string>
#include <vector>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<functional>
#include<list>
#include<deque>
#include<bitset>
#include<set>
#include<map>
#include<unordered_map>
#include<unordered_set>
#include<cstring>
#include<sstream>
#include<complex>
#include<iomanip>
#include<numeric>
#include<cassert>
#define X first
#define Y second
#define pb push_back
#define rep(X,Y) for (int (X) = 0;(X) < (Y);++(X))
#define reps(X,S,Y) for (int (X) = S;(X) < (Y);++(X))
#define rrep(X,Y) for (int (X) = (Y)-1;(X) >=0;--(X))
#define rreps(X,S,Y) for (int (X) = (Y)-1;(X) >= (S);--(X))
#define repe(X,Y) for ((X) = 0;(X) < (Y);++(X))
#define peat(X,Y) for (;(X) < (Y);++(X))
#define all(X) (X).begin(),(X).end()
#define rall(X) (X).rbegin(),(X).rend()
#define eb emplace_back
#define UNIQUE(X) (X).erase(unique(all(X)),(X).end())
#define Endl endl

using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
template<class T> using vv=vector<vector<T>>;
template<class T> ostream& operator<<(ostream &os, const vector<T> &t) {
os<<"{"; rep(i,t.size()) {os<<t[i]<<",";} os<<"}"<<endl; return os;}
template<class S, class T> ostream& operator<<(ostream &os, const pair<S,T> &t) { return os<<"("<<t.first<<","<<t.second<<")";}
template<class T> inline bool MX(T &l,const T &r){return l<r?l=r,1:0;}
template<class T> inline bool MN(T &l,const T &r){return l>r?l=r,1:0;}
#define out(args...){vector<string> a_r_g_s=s_p_l_i_t(#args, ','); e_r_r(a_r_g_s.begin(), args); }
vector<string> s_p_l_i_t(const string &s, char c){vector<string> v;int d=0,f=0;string t;for(char c:s){if(!d&&c==',')v.pb(t),t="";else t+=c;if(c=='\"'||c=='\'')f^=1;if(!f&&c=='(')++d;if(!f&&c==')')--d;}v.pb(t);return move(v);}
void e_r_r(vector<string>::iterator it) {}
template<typename T, typename... Args> void e_r_r(vector<string>::iterator it, T a, Args... args){ if(*it==" 1"||*it=="1") cerr<<endl; else cerr << it -> substr((*it)[0] == ' ', it -> length()) << " = " << a << ", "; e_r_r(++it, args...);}
template<typename T>vector<T> table(int n, T v){ return vector<T>(n, v);}
template <class... Args> auto table(int n, Args... args){auto val = table(args...); return vector<decltype(val)>(n, move(val));}
const ll MOD=1e9+7;

int main(){
  ios_base::sync_with_stdio(false);
  cout<<fixed<<setprecision(0);
	int n,m;
	cin>>n>>m;
	vector<string> ss(n);
	rep(i,n) cin>>ss[i];
	vector<int> cnt_(200);
	for(string s:ss){
		for(char c:s) ++cnt_[c];
	}
	vector<int> cnt(5);
	rep(i,200){
		int t=cnt_[i];
		cnt[4]+=t/4; t%=4;
		cnt[2]+=t/2; t%=2;
		cnt[1]+=t;
	}
	vector<int> ans;
	if(n%2==m%2){
		if(n%2){
			ans={0,1,n/2+m/2};
		}else{
			ans={0,0,0};
		}
	}else{
		if(n%2)	ans={0,0,m/2};
		else 	ans={0,0,n/2};
	}
	ans.pb(0);
	ans.pb(n*m);
	rep(i,4) ans.back()-=ans[i]*i;
	if(ans.back()%4){
		return 1;
			cout<<"No"<<endl;
			return 0;
		}
		
	ans.back()/=4;
	rrep(i,5){
		if(i==3&&cnt[i]){
			cout<<"No"<<endl;
			return 0;
		}
		if(ans[i]>cnt[i]){
			cout<<"No"<<endl;
			return 0;
		}
		int t=ans[i]-cnt[i];
		cnt[i/2]-=t*2;
	}
	cout<<(cnt[0]?"No":"Yes")<<endl;
  return 0;
}


Measured memory_bytes: 256