#include <bits/stdc++.h>

template<class T>
void print(const T &t) { std::cout << t << '\n'; }

template<class Head, class... Tail>
void print(const Head &head, const Tail &... tail) {
    std::cout << head << ' ';
    print(tail...);
}

using v = std::vector<int>;
using ll = long long;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);

    int n, x;
    std::cin >> n >> x;
    v s(n);
    for (auto &i: s) {
        std::cin >> i;
    }

    ll sum = 0;
    for (int i = 0; i < n; ++i) {
        sum += s[i];
    }
    sum -= ll(n - 1) * x;

    print(sum);
}