#include<fstream.h>
ifstream fin("text.in");
ofstream fout("text.out");
int o,i,k,contor,lung;
char c,v[1001];
int main()
{
	i=1;
	while(fin.get(c)&&c!='\n')
	{
		v[i]=c;
		if((v[i]>='a'&&v[i]<='z')||(v[i]>='A'&&v[i]<='Z'))
			lung++;
		if(((v[i]>='a'&&v[i]<='z')||(v[i]>='A'&&v[i]<='Z'))&&v[i-1]==' ')
			o++;
		i++;
	}
	i--;
	if(v[i]=='.'||v[i]=='!'||v[i]=='?')
		o++;
	fout<<lung/o;
	return 0;
}