#include<cstdio>
#include<string.h>
#include<fstream>
using namespace std;
char s[10000000];
int main()
{
    /*FILE *f=fopen("text.in","r");
    FILE *g=fopen("text.out","w");*/
    fstream f,g;
    f.open("text.in",ios::in);
    g.open("text.out",ios::out);
    char *p;
    int lungime=0,numar=0;
    f.getline(s,10000000);

    p=strtok(s," ~!@#$%^&*()_+{}|<->?/.,';\][=-0987654321`");
    while(p!=NULL)
    {
        lungime=lungime+strlen(p);
        numar=numar+1;
        p=strtok(NULL," ~!@#$%^&*()_+{}|<>?/.,-';\][=-0987654321`");
    }
    g<<lungime/numar;
}