class Solution {
public:
int minimumPushes(string word) {
int cnt[26] = {0};
for (auto c: word) cnt[c - 'a'] ++ ;
sort(cnt, cnt + 26, greater<int>());
int res = 0;
for (int i = 0; i < 26; i ++ )
res += cnt[i] * (i / 8 + 1);
return res;
}
};