#include<cstdio>
#include<string.h>
using namespace std;
int i,cnt,cuv,n;
char *p,s[600000];
int main()
{
    freopen("text.in","r",stdin);
    freopen("text.out","w",stdout);
    gets(s);
    n=strlen(s);
    for(i=0;i<n;i++)
    {
        if(s[i]<='z'&&s[i]>='a')
            cnt++;
        if(s[i]<='Z'&&s[i]>='A')
            cnt++;
    }
    p=strtok(s,"., !?-");
    while(p!=NULL)
    {
        cuv++;
        p=strtok(NULL,"., !?-");
    }
    printf("%d",cnt/cuv);
    return 0;
}