#include <cstdio>

using namespace std;

int main() {
    
    freopen("text.in", "r", stdin);
    freopen("text.out","w", stdout);

    int nr = 0;
    int sum = 0;
    
    char ch;
    int str_len = 0 ;
    
    while( scanf("%c",&ch) != EOF ) {
        
        if( (ch >= 'a' && ch <= 'z') ||
            (ch >= 'A' && ch <= 'Z') )
            str_len++;
        else 
        if( str_len != 0 ){
            sum += str_len;
            nr++;
            str_len = 0;
        }
    }
    
    printf("%d", sum / nr );
    
    return 0;
    
}