#include <fstream>
#include <cstring>
using namespace std;

ifstream f ("text.in");
ofstream g ("text.out");

char c[100005];
int j=1,nrcuv,nrlit,i;

int main ( void ) { 
	
	f.get(c,100003);
	for ( i = 1 ; i <= strlen(c) ; i++ ) 
	{			if ( (c[i-1] >= 'a' && c[i-1] <= 'z') || (c[i-1] >= 'A' && c[i-1] <= 'Z') )
				{
					if ( (c[i] < 65 || c[i] > 90 ) && (c[i] < 97 || c[i] > 122) )
						nrcuv++;
				}
		if ( (c[i] >= 'a' && c[i] <= 'z') || (c[i] >= 'A' && c[i] <= 'Z') )
			nrlit++;
	}
	g<< nrlit/nrcuv;
}