#include<iostream>
#include<cstdio>
#define MN 3000000
#define INF 10000000000000000LL
#define ll long long
#define getchar() (*S++)
using namespace std;
char B[1<<26],*S=B;
inline int read()
{int x = 0;  char ch = getchar();while(ch < '0' || ch > '9') ch = getchar();while(ch >= '0' && ch <= '9'){x = x * 10 + ch - '0';ch = getchar();}return x;
}int n,q[MN+5],top,tail;
ll m,t,f[MN+5],mn=INF,s[MN+5];inline ll get1(int x,int y)
{while(top>=tail&&q[tail]<y) tail++;if(top<tail)return INF;return f[q[tail]]+t+s[x]-s[q[tail]];
}inline void ins(int x)
{while(top>=tail&&f[x]-s[x]<f[q[top]]-s[q[top]]) --top;q[++top]=x;
}int main()
{freopen("trade.in","r",stdin);freopen("trade.out","w",stdout);fread(B,1,1<<26,stdin);n=read();m=read();t=read();for(int i=1;i<=n;i++)s[i]=read();for(int i=1,j=0;i<=n;i++)    {while(j<i&&2*s[i]-2*s[j+1]>=t)mn=min(mn,f[j]-2*s[j+1]-s[j]),++j;ll res1,res2;res1=j<i?get1(i,j):INF;res2=j?mn+3*s[i]:INF;f[i]=min(res1,res2);ins(i);}printf("%lld\n",f[n]+m-s[n]);return 0;
}

#include<iostream>
#include<cstdio>
#define MN 3000000
using namespace std;
inline int read()
{int x = 0;; char ch = getchar();while(ch < '0' || ch > '9')  ch = getchar();while(ch >= '0' && ch <= '9'){x = x * 10 + ch - '0';ch = getchar();}return x;
}int n;
int x[MN+5],now=0,move=0,ans=0;
char s[MN+5],s2[MN+5];int main()
{freopen("string.in","r",stdin);freopen("string.out","w",stdout);n=read();scanf("%s",s+1);scanf("%s",s2+1);for(register int i=n,k=n;i;i--){if(k>i&&s2[i]!=s[i]) k=i;now+=x[i+move],x[i+move]=0;if(k<=i&&s2[i]!=s[k]){while(k&&s[k]!=s2[i]) --k;if(!k) return 0*puts("-1");move++,x[k+move-1]-=1,++now;ans=max(ans,now); }}printf("%d\n",ans);return 0;
}

#include<iostream>
#include<cstdio>
#define ll long long
using namespace std;
inline int read()
{int x = 0 , f = 1; char ch = getchar();while(ch < '0' || ch > '9'){ if(ch == '-') f = -1;  ch = getchar();}while(ch >= '0' && ch <= '9'){x = x * 10 + ch - '0';ch = getchar();}return x * f;
}struct edge{int to,next,kind;}e[2000005];
int head[1000005],cnt=0,n,num,m,sum,col[1000005],cou[5];
ll ans=0;
bool mark[1000005],flag;
inline void ins(int f,int t){e[++cnt]=(edge){t,head[f]};head[f]=cnt;}void dfs(int x)
{mark[x]=1;num++;cou[col[x]]++;for(int i=head[x];i;i=e[i].next,++sum)if(!mark[e[i].to]) col[e[i].to]=(col[x]+((i&1)?1:-1)+3)%3,dfs(e[i].to);else if(col[e[i].to]!=(col[x]+((i&1)?1:-1)+3)%3) flag=false;
}void solve(int i)
{cou[0]=cou[1]=cou[2]=0;flag=true;num=0;sum=0;dfs(i);sum/=2;if(flag) {if(cou[0]&&cou[1]&&cou[2]) ans+=1LL*cou[0]*cou[1]+1LL*cou[2]*cou[0]+1LL*cou[1]*cou[2]-sum; }elseans+=1LL*num*num-sum;
}int main()
{freopen("matrix.in","r",stdin);freopen("matrix.out","w",stdout);n=read();m=read();for(register int i=1;i<=m;i++){int u=read(),v=read();ins(u,v);ins(v,u);}for(register int i=1;i<=n;i++)if(!mark[i]&&head[i])solve(i);printf("%lld\n",ans+m);return 0;
}