#include <fstream>
#include <string.h>
using namespace std;
ifstream f("text.in");
ofstream g("text.out");

int main()
{
    int i, nrCuvinte=0, nrLitere=0;
    char a[10000], *p;
    f.get(a, 10000);
    p = strtok(a, " ");
    while (p)
    {
        nrCuvinte++;
        for (i=0; i<strlen(p); i++)
            if ((p[i] >= 'a' && p[i] <= 'z') || (p[i]>='A' && p[i]<='Z'))
                nrLitere++;
            else if (i != 0 && !((p[i] >= 'a' && p[i] <='z') || (p[i] >='A' && p[i] <= 'Z')) && ((p[i-1] >= 'a' && p[i-1] <='z') ||
                                               (p[i-1] >='A' && p[i-1] <= 'Z')) &&
                                              ((p[i+1] >= 'a' && p[i+1] <='z') ||
                                               (p[i+1] >='A' && p[i+1] <= 'Z')))
                                                nrCuvinte++;
        p = strtok(NULL, " ");
    }
    g<<nrLitere/nrCuvinte;
    return 0;
}