#include<bits/stdc++.h>
#define ALL(v) std::begin(v),std::end(v)
using lint=long long;
using ld=long double;
template<class T>using numr=std::numeric_limits<T>;
int main(){
    std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);
    std::cout.setf(std::ios_base::fixed);std::cout.precision(15);
    lint h,w;std::cin>>h>>w;
    std::vector<lint>a(26);
    for(lint i=0;i<h*w;i++){
        char c;std::cin>>c;
        a.at(c-'a')++;
    }
    std::cout<<(
        std::count_if(ALL(a),[](lint x){return x%2;})<=1
        &&std::count_if(ALL(a),[](lint x){return !(x%2)&&x%4;})<=(h/2)*(w%2)+(w/2)*(h%2)
        ?"Yes":"No")<<'\n';
}
