# include <iostream.h>
# include <fstream.h>
#include<math.h>
int i,nr1,nr,j;
char s[256],*p,sep[]=" '-.!?:;"; 
int main()
{
	
ifstream f("text.in");
ofstream g("text.out");
f.get(s,256);
nr1=0;
for(i=0;i<strlen(s);i++)
	if((s[i]>='a' && s[i]<='z') || (s[i]>='A' && s[i]<='Z'))
		nr1++;
nr=0;
p=strtok(s,sep);
while(p!=0)
{
	nr++;
	p=strtok(0,sep);
}
g<<nr1/nr;
f.close();
g.close();
return 0;
}