#include <iostream>
#include <fstream>
#include <cstring>
#define nmax 100000000
using namespace std;
ifstream f("text.in");
ofstream g("text.out");
char v[nmax];
char tok[]=".!- ?,:;";
long lit,nr;
int main()
{
    f.getline(v,nmax);
    char *p;
    p=strtok(v,tok);
    while(p!=NULL)
    {
        lit += strlen(p);
        p = strtok(NULL,tok);
        nr ++;
    }
    g<<lit/nr;
    return 0;
}