#include<cstdio>
#include<cstring>

void cit(int &k, int &l)
{
	char x;
	while(!feof(stdin))
	{
		scanf("%c",&x);
		if(x==' '||x=='/' || x=='-'||x=='\t'||x=='\n')
			k++;
		else
			if(97<=int(x)<=122 || 65<=int(x)<=90)
			l++;
	}
}

void afis(int k, int l)
{
	printf("%d",l/k);
}



int main()
{
	freopen("text.in","r",stdin);
	freopen("text.out","w",stdout);
	
	int k=0,l=0;
	
	
	cit(k,l);
	afis(k,l);
}