Valentine's Day '19 J3 - Love!

    1#include <bits/stdc++.h>
    2using namespace std;
    3using ll = long long;
    4using i128 = __int128;
    5const int inf = 1e9;
    6const ll INF = 1e18; //❄️
    7int main() {
    8    ios::sync_with_stdio(0); cin.tie(0); 
    9    string s; cin >> s;
    10    ll l = 0, lo = 0, lov = 0, love = 0;
    11    for (int i = 0; i < s.size(); i++) {
    12        char c = s[i];
    13        if (c == 'l') l++;
    14        if (c == 'o') lo += l;
    15        if (c == 'v') lov += lo;
    16        if (c == 'e') love += lov;
    17    }
    18    cout << love << '\n';
    19    return 0;
    20}