#include "bits/extc++.h"
using namespace std;
template <typename T, typename... U>
void dbgh(const T& t, const U&... u) {
cerr << t;
((cerr << " | " << u), ...);
cerr << endl;
}
#ifdef DEBUG
#define dbg(...) \
cerr << "L" << __LINE__ << " [" << #__VA_ARGS__ << "]: "; \
dbgh(__VA_ARGS__)
#else
#define dbg(...)
#define cerr \
if (false) \
cerr
#endif
using ll = long long;
#define endl "\n"
#define long int64_t
#define sz(x) int(std::size(x))
ll minimum_walk(vector<int> arr, int kv) {
int n = sz(arr), trans[n - 1] {};
for (int i = 0; i < n; i++) {
for (int j = i; j < arr[i]; j++) {
trans[j]++;
}
}
ll ans = 0;
for (auto& a : trans) {
a = max(a, 1);
ans += a * 2;
}
return ans;
}
