#include <cstdio>
#include <cstring>
#include <cctype>

using namespace std;

#define inFile "text.in"
#define outFile "text.out"
#define MAX_LEN 2000000

char S[MAX_LEN];

int main() {
    FILE *in = fopen(inFile, "r");
    FILE *out = fopen(outFile, "w");

    int len, i, j, sumLen = 0, nWords = 0;

    fgets(S, MAX_LEN, in);
    len = strlen(S);

    for(i = 0; i < len; i++) {
        if(isalpha(S[i])) {
            j = i;
            while(isalpha(S[i])) i++;
            sumLen += i-j;
            nWords++;
        }
    }

    fprintf(out, "%d\n", sumLen / nWords);

    return 0;
}