#include <bits/stdc++.h>   using namespace std;   int main() {     int n = 0;     long long moves = 0;     cin >> n;     vector<long long> arr(n, 0);     for (int i = 0; i < n; i++) cin >> arr[i];     long long last = arr[0];     long long min = INT_MAX;     bool found = false;     for (int i = 1; i < n; i++) {       if (arr[i] < arr[i - 1]) {         if (arr[i] < min) {           min = arr[i];           found = true;         }       }       if (arr[i] > arr[i - 1] || i + 1 == n) {         if (found) {           moves += last - min;           found = false;         }         min = INT_MAX;         last = arr[i];       }     }     cout << moves << endl;     return 0;   }   