#include <iostream>
#include <string>

using namespace std;

int main() {

    string input;
    int index = 0;
    while (getline(cin, input)) {
        int record[26] = {0};
        for (int i = 0; i < input.length(); i++) {
            index = input[i] - 'a';
            record[index]++;
        }
        for (int i = 0; i < 26; i++) {
            cout << (char) ('a' + i) << ":" << record[i] << endl;
        }
        cout << endl;
    }
    return 0;
}