#include <bits/stdc++.h>
using namespace std;

ifstream in("text.in");
ofstream out("text.out");

char s,*p;
int n,litere=0,cuvinte=0,S;

void solve(){

while(in.get(s))
{
  if(isalpha(s))
    litere++;
  else
  {
      if(litere>0)
     cuvinte++;
     S=S+litere;
    litere=0;
  }
}

out<<S/cuvinte;



}

int main(){

solve();


return 0;
}