#include <bits/stdc++.h>
using namespace std;
int main(){
string an;
int a=0,b=0,c=0,d=0,e=0,f=0,g=0,h=0,i=0,j=0,k=0,l=0,m=0,n=0,o=0,p=0,q=0,r=0,s=0,t=0,u=0,v=0,w=0,x=0,y=0,z=0;
cin>>an;
int len=an.length();
for(int i=0;i<len;i++){
if(an[i]'a')a++;
else if(an[i]'b')b++;
else if(an[i]'c')c++;
else if(an[i]'d')d++;
else if(an[i]'e')e++;
else if(an[i]'f')f++;
else if(an[i]'g')g++;
else if(an[i]'h')h++;
else if(an[i]'i')i++;
else if(an[i]'j')j++;
else if(an[i]'k')k++;
else if(an[i]'l')l++;
else if(an[i]'m')m++;
else if(an[i]'n')n++;
else if(an[i]'o')o++;
else if(an[i]'p')p++;
else if(an[i]'q')q++;
else if(an[i]'r')r++;
else if(an[i]'s')s++;
else if(an[i]'t')t++;
else if(an[i]'u')u++;
else if(an[i]'v')v++;
else if(an[i]'w')w++;
else if(an[i]'x')x++;
else if(an[i]'y')y++;
else if(an[i]'z')z++;
}
if(a1)cout<<a;
else if(b1)cout<<"b";
else if(c1)cout<<"c";
else if(d1)cout<<"d";
else if(e1)cout<<"e";
else if(f1)cout<<"f";
else if(g1)cout<<"g";
else if(h1)cout<<"h";
else if(i1)cout<<"i";
else if(j1)cout<<"j";
else if(k1)cout<<"k";
else if(l1)cout<<"l";
else if(m1)cout<<"m";
else if(n1)cout<<"n";
else if(o1)cout<<"o";
else if(p1)cout<<"p";
else if(q1)cout<<"q";
else if(r1)cout<<"r";
else if(s1)cout<<"s";
else if(t1)cout<<"t";
else if(u1)cout<<"u";
else if(v1)cout<<"v";
else if(w1)cout<<"w";
else if(x1)cout<<"x";
else if(y1)cout<<"y";
else if(z1)cout<<"z";
else cout<<"no";
return 0;
}
