#include <fstream>
#include <cstring>
using namespace std;
#define MAXN 1100000
char t[MAXN];
int main()
{
    char *p, *p_vechi;
    unsigned int i = 0, suma = 0;
    ifstream fin("text.in");
    ofstream fout("text.out");
    fin.getline(t,MAXN);
    fin.close();
    p = strtok(t," ,.-!");
    while(p){
        p_vechi = p;
        p = strtok(NULL, " ,.-!");
        suma += strlen(p_vechi);
        i++;
    }
    if(i) fout << suma/i << "\n";
    fout.close();
    return 0;
}