#include <cstdio>
#include <cstring>
#define DIM 4000005

char s[DIM];

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

int j,lg,i,nrcuv,litere,inc;

    fgets(s, DIM - 1, stdin);
    lg = strlen(s);
        if( s[lg-1] == '\n' ) lg--;

for( nrcuv = litere = 0, i = 0; i < lg ; )
{
    for( j = i; j < lg && ( s[j]<='a' || s[j]>='z') && ( s[j]<='A' || s[j]>='Z'  ); ++j );

    for( inc = j; j < lg && ( (s[j]>='a' && s[j]<='z') || ( s[j]>='A' && s[j]<='Z' ) ) ;++j );
    litere += j - inc;
    if( j - inc ) nrcuv++;

    i = j;
}

    if(nrcuv)
        printf("%d\n",litere/nrcuv);
    else
        printf("0\n");


return 0;
}