#include <stdio.h>
#include <bits/stdc++.h>
using namespace std;
class FrogJump1 {
public:
int totalCost(vector<int>& heights, int n) {
vector<int> cost(n);
cost[0] = 0;
cost[1] = abs(heights[0] - heights[1]);
for(int i = 2; i < n; i++) {
cost[i] = min(cost[i-1] + abs(heights[i] - heights[i-1]), cost[i-2] + abs(heights[i] - heights[i-2]));
}
return cost[n-1];
}
};
int main() {
int n;
vector<int> heights(n);
cin >> n;
for(int i = 0; i < n; ++i) {
cin >> heights[i];
}
FrogJump1 *obj = new FrogJump1();
cout << obj->totalCost(heights, n) << endl;
return 0;
}
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