#include <fstream>
#include <string>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
string s, sc;
int main()
{
    long long n=0, nr=0;
    int i, j;
    while(getline(fin, s))
    {
       for(i=0;i<s.size();i++)
        {
        if((s[i]>='a' and s[i]<='z') or (s[i]>='A' and s[i]<='Z'))
        {
            sc.push_back(s[i]);
            for(j=i+1;j<s.size();j++)
            {
                 if(!((s[j]>='a' and s[j]<='z') or (s[j]>='A' and s[j]<='Z')))
                    break;
                 else
                    sc.push_back(s[j]);
            }
            n=n+sc.size();
            sc.clear();
            nr++;
            i=j;
        }
       }
    }
    fout<<n/nr<<"\n";
    return 0;
}