A_Night_at_the_Museum.cpp

#include <bits/stdc++.h>
using namespace std;

int main()
{
    string s;
    cin >> s;
    char curr = 'a';
    int ans = 0;
    for (char c : s) {
        int diff = abs(c - curr);
        ans += min(diff, 26 - diff);
        curr = c;
    }
    cout << ans << endl;
    return 0;
}