program mountain;
Uses sysutils, Math;

const
    MAXN = 100005;

var
    ANS, N, i, j,h,w, maxMountainLength, lung : LongInt;
    P, leftLIS, rightLIS  : Array[0..MAXN-1] of LongInt;
    rimossi : Ansistring;
    rimosso: boolean;
begin
    (*assign(input,  'input.txt');  reset(input);
    assign(output, 'output.txt'); rewrite(output);*)  

    ReadLn(N);
    rimossi:=''; lung:=N;
    for i:=0 to N-1 do begin
                        Read(P[i]);
                        rimossi:=rimossi+IntTostr(P[i]);
                       end;  
    ReadLn();
    rimosso:=false; w:=2; h:=1;
    while h<5 do 
       begin
        w:=2; rimosso:=false;
        while w<lung do
              begin
                if  (rimossi[w]<rimossi[w-1]) and (rimossi[w]<rimossi[w+1]) then
                                                                              begin
                                                                                delete(rimossi,w,1);
                                                                                lung:=lung-1;
                                                                                rimosso:=true;
                                                                              end;                    
                for i:=1 to lung  do P[i-1]:=StrToInt(rimossi[i]); 
       
    	ANS := 0; 
	(*leftLIS[i] stores the length of longest increasing subsequence ending at index i*)
	(*rightLIS[i] stores the length of longest decreasing subsequence starting at index i*)

  	 for i:=0 to  lung-1 do begin leftLIS[i]:=1; rightLIS[i]:=1; end;

	(*Calculate LIS from left to right for each position*)
  
   	for i := 1 to lung-1 do
           for j:= 0 to i-1 do
                begin
                  if (P[i] > P[j]) then leftLIS[i] := max(leftLIS[i], leftLIS[j] + 1);                          
                end;  
  
	(* Calculate LIS from right to left (decreasing subsequence) for each position*)

   	for i := lung - 2 downto 0 do
            for  j := i + 1 to lung-1 do
               begin
                if (P[i] > P[j]) then rightLIS[i] := max(rightLIS[i], rightLIS[j] + 1);                
	       end;
        (* Find the maximum length of mountain subsequence*)
 	  maxMountainLength := 0;
  	 for i := 0 to lung-1 do
	(*A valid mountain peak must have at least one element on both sides*)
	(*leftLIS[i] > 1 ensures there's at least one element before peak*)
	(*rightLIS[i] > 1 ensures there's at least one element after peak*)
  	 if (leftLIS[i] >= 1) and (rightLIS[i] >= 1)  then
  	(*Total mountain length with peak at i Subtract 1 because peak is counted in both leftLIS and rightLIS*)
         maxMountainLength := max(maxMountainLength, leftLIS[i] + rightLIS[i] - 1);
 	(* Minimum removals = total elements - maximum mountain length*)
  	 ANS:= N - maxMountainLength; 
        	w:=w+1;
            end;         
          h:=h+1;   
       end;  
   WriteLn(ANS);
end.