#include <fstream>
#include <cstring>
using namespace std;
#define MAXN 1100000
char t[MAXN];
int main()
{
    char *p, sir[] = " `~1234567890!@#$%^&*()-+={}[]|:;'<>,.?/\\";
    unsigned int i = 0, suma = 0;
    ifstream fin("text.in");
    ofstream fout("text.out");
    while(!fin.eof()){
        fin.getline(t,MAXN);
        p = strtok(t, sir);
        while(p){
            suma += strlen(p);
            p = strtok(NULL, sir);
            i++;
        }
    }
    if(i) fout << suma/i << "\n";
    fin.close();
    fout.close();
    return 0;
}