#include <cstdio>
#include <cstring>

using namespace std;

char vec[ 4194304 + 10 ];
char *p;

int main() {
    
    freopen("text.in", "rb", stdin);
    freopen("text.out","w", stdout);
    
    fread( vec , sizeof(char),  4194304 + 10 , stdin );
    
    p = strtok( vec , " -,;.!?=:" );

    long long nr = 0;
    long long sum = 0;
    
   
    while( p != NULL ) {
        
        sum += strlen( p );
        nr++;
        p = strtok( NULL , " -,;.!?:" );
        
    }
    
    printf("%lld", sum / nr );
    
    fclose(stdin);
    
    return 0;
    
}