#include<bits/stdc++.h>
#define N 1048579
using namespace std;
ifstream in("text.in");
ofstream out("text.out");

char f[N],*p,sep[]={" , -;.:?!"};
int l,nc;

int main(){
in.get(f,N-1);
//in.get();
in.close();
p=strtok(f,sep);
while(p){
    l+=strlen(p);
    ++nc;
    p=strtok(NULL,sep);}

    if(!nc) out<<0<<"\n";
        else
    out<<l/nc<<"\n";
out.close();
return 0;}