#define _USE_MATH_DEFINES #include <cstdio> #include <iostream> #include <sstream> #include <fstream> #include <iomanip> #include <algorithm> #include <cmath> #include <complex> #include <string> #include <vector> #include <list> #include <queue> #include <stack> #include <set> #include <map> #include <bitset> #include <numeric> #include <limits> #include <climits> #include <cfloat> #include <functional> #include <iterator> using namespace std; const long long INF = LLONG_MAX / 2; int main() { int n, p; cin >> n >> p; vector<int> h(n); for(int i=0; i<n; ++i) cin >> h[i]; vector<vector<long long> > dp(n, vector<long long>(2, INF)); dp[0][0] = 0; for(int i=0; i<n-1; ++i){ for(int j=0; j<2; ++j){ for(int k=0; k<2; ++k){ dp[i+1][k] = min(dp[i+1][k], dp[i][j] + p); } } dp[i+1][0] = min(dp[i+1][0], dp[i][0] + max(0, h[i+1] - h[i])); dp[i+1][1] = min(dp[i+1][1], dp[i][1] + max(0, h[i] - h[i+1])); } long long ans = min(dp[n-1][0], dp[n-1][1]); cout << ans << endl; return 0; }