#include <fstream>
#include <string.h>
using namespace std;
ifstream fin("text.in");
ofstream fout("text.out");
char x[1000000];
int l,nr,n,i;
int main()
{
    fin.get();
    fin.get(x,1000000,'\n');
    n=strlen(x);
    l=0;
    nr=0;
    for(i=0;i<n-1;i++)
        {
        if(x[i]>='a'&&x[i]<='z'||x[i]>='A'&&x[i]<='Z')
        l++;
        else
         if(x[i+1]>='a'&&x[i+1]<='z'||x[i+1]>='A'&&x[i+1]<='Z')
            nr++;
         }

        fout<<l/nr;
    return 0;
}