#include<stdio.h>
#include<ctype.h>

using namespace std;

char c;

int main(){
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    int cuv=0,len=0,lencmp=0;
    while(scanf("%c",&c)!=EOF){
        if(isalpha(c)) ++len;
        else if(len){
            lencmp+=len;
            ++cuv;
            len=0;
        }
    }
    printf("%d\n",lencmp/cuv);
    return 0;
}