#include<fstream.h>
#include<string.h>

ifstream fin("text.in");
ofstream fout("text.out");

int main()
{char c[100000],*p;
long s=0,nr=0;
fin.get(c,100000);
p=strtok(c," ,.;:-!?`()[]+*{}123456789~@#$%^&");
while(p)
 {s=s+strlen(p);
 nr++;
 p=strtok(NULL," ,.;:-!?`()[]+*{}123456789~@#$%^&");
 }
fout<<s/nr;
fin.close();
fout.close();
return 0;
}