#include <iostream>
#include<fstream>

using namespace std;
string s;
int nr,nrc=0,k,i;
int main()
{
    ifstream f("text.in");
    ofstream g("text.out");
    while(f>>s)
        {
            nr++;k=0;
            for(i=0;i<s.size();i++)
            if(((s[i]>='a')&&(s[i]<='z'))||((s[i]>='A')&&(s[i]<='Z'))){k=1;break;
            }
            if(k==1)nrc+=s.length();

        }
    g<<nrc/nr;
    return 0;
}