#include<stdio.h>
#include<string.h>

char s[100001],c;
int n,k,j,i,cate=0,sum=0,ma,ci,cate2;

int main(){

freopen ("text.in","r",stdin);
freopen ("text.out","w",stdout);

gets(s);
n=strlen(s);

for (i=0;i<=n;i++){
    cate=0;
    while ((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z')){
        cate++;i++;}
    sum+=cate;}

//sum

for (i=0;i<=n;i++){
    if ((s[i]==' '||s[i]=='-'||s[i]==','||s[i]=='.'||s[i]=='?'||s[i]=='!'||s[i]=='@')&&(s[i+1]>='a'&&s[i+1]<='z')||(s[i+1]>='A'&&s[i+1]<='Z'))
        cate2++;}

printf ("%d",sum/cate2);

return 0;
}