#include <bits/stdc++.h>
using namespace std;
#define print(l) for(auto i:l) cout<<i<<" ";cout<<endl;
#define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i];
#define int long long
#define pb push_back
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define all(l) l.begin(),l.end()
#define pii pair<int,int>
#define fi first
#define se second
const int M = 1e9+7;
const int inf = 1e18;
void io(){
#ifndef ONLINE_JUDGE
freopen("input.in","r",stdin);
// freopen("outputf.in","w",stdout*);
#endif
ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
cin.tie(0), cout.tie(0);
cout << fixed<<setprecision(9);
}
int bp(int x, int y, int p){
int res = 1;
x = x % p;
while (y > 0) {
if (y & 1)
res = (res * x) % p;
y = y >> 1;
x = (x * x) % p;
}
return res;
}
int MI(int n, int p){
return bp(n, p - 2, p);
}
int mul(int x,int y, int p){
return x * 1ull * y % p;
}
int di(int x,int y, int p){
return mul(x, MI(y, p), p);
}
int n , m , k , q;
void yn(int t){
if(t){
cout<<"YES"<<endl;
}
else{
cout<<"NO"<<endl;
}
}
void solve(int testcase_number){
cin>>n>>m;
if(n == 1){
cout<<0<<endl;
return;
}
input(int,l,n);
vector<int>vis(n,0);
for(int i = 0;i<m;i++){
cin>>q>>q;
}
int mx = 0;
for(int i:l){
mx = max(mx,i);
}
int li = 0;
int r = 0;
for(int i = 1;i<n;i++){
if(l[i]<l[i-1]){
if(l[i-1] == mx){
break;
}
l[i] = l[i-1];
}
vis[i-1] = 1;
}
reverse(all(l));
reverse(all(vis));
for(int i = 1;i<n;i++){
if(l[i]<l[i-1]){
if(l[i-1] == mx){
break;
}
l[i] = l[i-1];
}
vis[i-1] = 1;
}
reverse(all(l));
reverse(all(vis));
int ans = -1;
for(int i = 0;i<n;i++){
if(vis[i] == 0){
l[i] = mx;
ans++;
}
}
vector<int>v1,v2;
int f = 0;
for(int i = 0;i<n;i++){
if(f == 0 and !vis[i]){
v1.pb(l[i]);
}
if(f and i-1>=0 and !vis[i-1] and vis[i]){
v2.pb(l[i-1]);
}
if(vis[i] == 0){
f = 1;
}
if(!f and vis[i]){
v1.pb(l[i]);
}
else if(f and vis[i]){
v2.pb(l[i]);
}
}
// print(l);
// pritn(vis);
reverse(all(v1));
// print(v1);
// print(v2);
int al = v1[0];
for(int i = 1;i<v1.size();i++){
if(v1[i] == al){
ans++;
}
else{
ans++;
al--;
}
}
ans+=al;
al = v2[0];
for(int i = 1;i<v2.size();i++){
if(v2[i] == al){
ans++;
}
else{
ans++;
al--;
}
}
ans+=al;
cout<<ans<<endl;
}
signed main(){
// io();
int t = 1;
// cin>>t;
for(int i = 1;i<=t;i++){
solve(i);
}
}
