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

char x[100],*q;
int s,k;
int main()
{
    f.getline(x,100);
    q=strtok(x," [];'\,./<>?:!@#$%^&*)(}{-+=_");
    while(q)
    {
        s=s+strlen(q);
        k++;
        q=strtok(NULL," [];'\,./<>?:!@#$%^&*)(}{-+=_");
    }
    g<<s/k;

    return 0;
}