#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const int LIM=2e5+7;
ll T[LIM], pref[LIM], suf[LIM];;
int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	int n, m, q;
	cin >> n >> m >> q;
	rep(i, n) cin >> T[i];
	rep(i, n) {
		pref[i]=T[i];
		if(i) pref[i]=max(pref[i], pref[i-1]);
	}
	for(int i=n-1; i>=0; --i) {
		suf[i]=T[i];
		if(i<n-1) suf[i]=max(suf[i], suf[i+1]);
	}
	ll ans=0;
	rep(i, n-1) ans+=min(T[i], T[i+1]);
	if(T[0]<=T[1]) {
		int l=0;
		while(l<n-1 && T[l]<=T[l+1]) ++l;
		ans+=T[l]-T[0];
	}
	if(T[n-1]<T[n-2]) {
		int l=n-1;
		while(l>0 && T[l]<T[l-1]) --l;
		ans+=T[l]-T[n-1];
	}
	for(int i=1; i<n-1; ++i) if(T[i-1]>T[i] && T[i]<=T[i+1]) {
		int l1=i;
		while(l1<n-1 && T[l1]<=T[l1+1]) ++l1;
		int l2=i;
		while(l2>0 && T[l2]<T[l2-1]) --l2;
		ans+=min(T[l1], T[l2])-T[i];
		if(T[l2]<=T[l1]) {
			if(pref[i]<=T[l1]) ans+=T[l1]-T[l2];
		} else {
			if(suf[i]<T[l2]) ans+=T[l2]-T[l1];
		}
	}
	cout << ans << '\n';
}