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

#define int long long
int n, k, p;

signed main(){
    freopen("defeat.in", "r", stdin);
    freopen("defeat.out", "w", stdout);
    cin.tie(0) -> ios::sync_with_stdio(0);
    cin >> n >> k >> p;
    int ans = 0;
    int ofs = 0;
    for(int i = 1;i <= n;i ++){
        int x; cin >> x; x += ofs;
        int delta = abs(k - x);
        ans += delta;
        if(x < k) ofs += delta;
        else ofs -= delta;
    }
    cout << ans << '\n';
    return 0;
}