#include "bits/stdc++.h" #include <unordered_set> #define rep(i,n) for(ll i = 0; i < n; i++) typedef long long ll; typedef unsigned long long ull; using namespace std; #define vll vector<vector<long long>> #define vl vector<long long> #define vi vector<int> #define vii vector<vector<int>> #define pb push_back #define pf push_front #define ld long double #define Sort(a) sort(a.begin(),a.end()) #define cSort(a,cmp) sort(a.begin(),a.end(),cmp) #define reSort(a) sort(a.rbegin(), a.rend()) static const ll llMAX = numeric_limits<long long>::max(); static const int intMAX = numeric_limits<int>::max(); static const ll llMIN = numeric_limits<long long>::min(); static const int intMIN = numeric_limits<int>::min(); static const ll d_5 = 100000; static const ll d9_7 = 1000000007; static const ll d_9 = 1000000000; static const double PI=3.14159265358979323846; template<class T> void Printvector(std::vector<T> a){ int size = a.size(); rep(i,size){ cout<<a[i]<<" "; } cout<<endl; } template<class T> void Printvector(std::vector<std::vector<T>> a){ int size = a.size(); rep(i,size){ int size2=a[i].size(); rep(j,size2){ cout<<a[i][j]<<" "; } cout<<endl; } cout<<endl; } ll digitpower(ll a,ll b){//aのb乗を計算 if(b==1){ return a; }else if(b==0){ return 1; } int mode=0; if(b%2==1){ ll tmp = digitpower(a,(b-1)/2); if(mode==1){ tmp%=d9_7; } tmp*=tmp; if(mode==1){ tmp%=d9_7; } tmp*=a; if(mode==1){ return tmp%d9_7; }else{ return tmp; } }else{ ll tmp = digitpower(a,(b)/2); if(mode==1){ tmp%=d9_7; } tmp*=tmp; if(mode==1){ tmp%=d9_7; } if(mode==1){ return tmp%d9_7; }else{ return tmp; } } } vl facs(2000010,-1); ll Factrial(ll num){ if(facs[num]!=-1){ return facs[num]; } if(num==1||num<=0){ return 1; }else if(num<0){ printf("ERROR_minus\n"); return 0; }else{ facs[num]=(num*Factrial(num-1))%d9_7; return facs[num]; } } long long modinv(long long a, long long m) {//modの逆元 long long b = m, u = 1, v = 0; while (b) { long long t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= m; if (u < 0) u += m; return u; } vl invs(2000010,-1); ll linercomb(ll n,ll k, ll mod){//n,kの線形時間で求める if(n<k)return 0; if(n<0)return 0; if(k==0 || k==n)return 1; ll ans=Factrial(n); if(invs[k]==-1){ invs[k]=modinv(Factrial(k),mod); } ans*=invs[k]; ans%=d9_7; ll k1=Factrial(n-k); k1%=mod; ans*=modinv(k1,mod); ans%=mod; return ans; } unordered_map<ll,ll> prime_factor(int64_t n) { unordered_map<ll,ll> ret; for(int64_t i = 2; i * i <= n; i++) { while(n % i == 0) { ret[i]++; n /= i; } } if(n != 1) ret[n] = 1; return ret; } template<class T> vector<T> getaccum(vector<T> a){ int size=a.size(); vector<T> ans(size); ans[0]=a[0]; for(int i=0;i<size-1;i++){ ans[i+1]=ans[i]+a[i+1]; //ans[i+1]%=d9_7; } return ans; } struct datas{ int item1; int item2; int score; };/* bool cmp(const datas &a, const datas &b) { return a.num < b.num; }*/ ll getaccumnum(vector<ll> accum,int l,int r){//閉区間[l,r]の総和 if(l==0){ return accum[r]; }else{ return accum[r]-accum[l-1]; } } int main(void){ int n; cin>>n; ll p; cin>>p; deque<ll> h; rep(i,n){ ll tmp; cin>>tmp; h.pb(tmp); } rep(i,n-1){ if(*h.begin()>=*(++h.begin())){ h.pop_front(); }else{ break; } } for(auto i=h.begin();i!=h.end();){ cout<<"state of h"<<endl; for(auto j:h){ cout<<j<<" "; } cout<<endl; auto i2=i+1; auto i3=i+2; if(i2==h.end())break; if(i3==h.end())break; cout<<"sequence"<<endl; cout<<*i<<" "<<*i2<<" "<<*i3<<endl; if((*i<=*i2<=*i3) || (*i>=*i2>=*i3)){ h.erase(i2); }else{ i++; } } cout<<"f"; n=h.size(); ll ans=0; for(auto itr=h.begin();itr!=(h.end());itr++){ cout<<*itr<<endl; auto itr2=itr; itr2++; if(itr2==h.end())break; if(*itr<*itr2){ ans+=min(*itr2-*itr,p); } } cout<<ans<<endl; } //<<std::setprecision(30)