#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
long long factorial(int n) {
    long long result = 1;
    for (int i = 1; i <= n; ++i) {
        result *= i;
    }
    return result;
}
long long combinations(int n, int r) {
    if (r > n || r < 0) return 0;
    return factorial(n) / (factorial(r) * factorial(n - r));
}

int countTeams(vector<int> skills, int minPlayers, int minLevel, int maxLevel) {
    vector<int> f;
    for (int skill : skills) {
        if (skill >= minLevel && skill <= maxLevel) {
            f.push_back(skill);
        }
    }

    int v = f.size();
    long long totalTeams = 0;
    for (int i = minPlayers; i <= v; ++i) {
        totalTeams += combinations(v, i);
    }
    return totalTeams;
}