#include<cstdio>
#include<cstring>
char s[100000];
long i,l,lung,nr;
int main(){
	freopen("text.in","r",stdin);
	freopen("text.out","w",stdout);
    //fgets(s,100000,stdin);
	while(fgets(s,100000,stdin))
		for(i=0;i<=(long)strlen(s);i++)
			if((s[i]>='a' && s[i]<='z')||(s[i]>='A' && s[i]<='Z')){
			lung++;
			if(l==0)nr++;
			l++;
			}
			else
				l=0;
    if(l>0){
		lung+=l;
		nr++;
	}
	if(nr==0)printf("0\n");
	else printf("%ld\n",(long)(lung/nr));
	fclose(stdin);
	fclose(stdout);
	return 0;
}