#include<fstream>
#include<cstring>
using namespace std;
FILE *f;
ofstream g("text.out");
long long nrl,nrcuv;
char c,c1;
int main()
{f=fopen("text.in","r");
fscanf(f,"%c%c",&c,&c1);
while(c!='\n')
{if(c>='a'&&c<='z'||c>='A'&&c<='Z')
	nrl++;
else
	if(c1>='a'&&c1<='z'||c1>='A'&&c1<='Z')
		++nrcuv;
c1=c;
fscanf(f,"%c",&c);
}
if(c1>='a'&&c1<='z'||c1>='A'&&c1<='Z')
	++nrcuv;
g<<nrl/nrcuv;
fclose(f);
g.close();
return 0;
}