// written by Eng. Abdullah Haydari
#include<bits/stdc++.h>
using namespace std;
int main(){
    int n; cin>>n;
    int h[n],memo[n];  // memo: memoization
    memo[n-1]=0;
    memo[n]=1e9; // Out of the array
    for (int i=0;i<n;i++)
        cin>>h[i];
    for (int i=n-2;i>=0;i--){
        int jump1=memo[i+1]+abs(h[i]-h[i+1]);
        int jump2=memo[i+2]+abs(h[i]-h[i+2]);
        memo[i]=min(jump1,jump2);
    }
    cout<<memo[0]<<endl;
}

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