#include<iostream>
using namespace std;
int main()
{
    int arr[]
    cin>>arr[];
    if((arr[]={0,1,2,3,4,5,6,7,8,9})||((arr[]={a.b.c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z}&&arr[]={A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z}))
    {
        cout<<arr[].length();
    }
    else
    {
        cout<<"Invalid input";
    }
}