10 5 5
2 3 4 5 6
 1 1 1
1
 1000000000000000000 10 68
9818112234872670 233245257111863071 266483628625876079 375103213040049805 431982380866113633 489732004669478331 501030096787260719 541800997319766183 551892546260532408 696178619227890200
 1000000000000000000 2 1
1 1000000000000000000
 33 32 1
1 2 3 4 5 6 7 8 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
 101 55 10
1 3 5 7 8 9 10 16 18 21 22 23 24 25 27 30 32 35 36 37 38 39 40 43 45 47 49 50 51 52 54 57 59 61 64 66 67 68 69 70 71 72 73 80 83 86 87 88 89 90 91 92 96 97 98
 1000000000000000000 5 1000
1 1000000000 1000000000000 1000000000000000 1000000000000001
 15 15 15
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
 21 21 20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
 45 43 2
1 2 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45
 107 20 13
5 9 20 25 26 30 37 45 51 58 62 73 82 87 89 90 99 101 104 106
 3 2 1
1 2
 1000000000 2 1000000000
1 1000000000
 11 7 3
2 3 4 5 6 7 11
 13 9 4
1 2 3 6 7 8 11 12 13
 1000000000000000000 2 1000000000
102306300054748096 267367244641009859
 16 7 5
2 3 4 5 6 15 16
 35 35 1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
 1000000000000000000 20 365
31881893160049984 103938857870698567 103962228223609431 140762820261865064 175962215264653912 239086305245565642 354522451098745823 383839975876242372 443471287955807705 478923027151493682 511195154588214957 619570919279066139 677571312513476877 705864797651447277 789633853044745934 867300890280086078 883297431113041450 891736036124527038 937306858250803630 990892290394455512

2
 1
 10
 2
 32
 15
 4
 1
 2
 35
 9
 2
 1
 4
 4
 2
 4
 35
 20

import sys, os, io
def rs(): return sys.stdin.readline().rstrip()
def ri(): return int(sys.stdin.readline())
def ria(): return list(map(int, sys.stdin.readline().split()))
def ws(s): sys.stdout.write(s + '\n')
def wi(n): sys.stdout.write(str(n) + '\n')
def wia(a): sys.stdout.write(' '.join([str(x) for x in a]) + '\n')
import math,datetime,functools,itertools,operator,bisect,fractions
from collections import deque,defaultdict,OrderedDict
from fractions import Fraction
from decimal import Decimal
    
def main():
    starttime=datetime.datetime.now()
    if(os.path.exists('input.txt')):
        sys.stdin = open("input.txt","r")
        sys.stdout = open("output.txt","w")

    for _ in range(1):
        n,m,k=ria()
        p=ria()
        i=0
        f=0
        c=0
        ans=0
        while i<m:
            f=i
            a=((p[i]-f+k-1)//k)
            for j in range(i+1,min(i+k,m)):
                b=((p[j]-f+k-1)//k)
                if b==a:
                    i+=1
                else:
                    break
            i+=1
            ans+=1
        print(ans)
                
            
        

        
        
        
          
        

                
        
            
            
        
        
                
                

        
            
            
        
            
        
        
        
        
                

        

                
            
             
            
            
        

        
        
        
            
            
            
                
        
                
        
            
        
              
        
                
            
                
                
                
        
            
        
        
                    
            
            
        
        
        
        
        
            
                
                
            
            
            
            
        


                
            
            

                    
        
        
                
        
        
                
                    
        
        
        
        
        
        
        
       
  
            
            

            
                
                
        
        
            
                    
            
            

        
        

    
                
                    
                
                
                
                    
                
        
        
        
        
        
        
        
            
            
        
        
        
            
        
                
        
        
            
            
        
        
                    
                    
        
        

                
                    
        
            
            
                
        
        
           
            
            
            

        
        
        


            
            
            
           
            
            
            
            
        
            
                
            
            
                            
                
            
            
        
            
            
            
            
            
            
        
        
                
                
                
                  
                    
                    
                
            
        
        
                
                
            
        
        
                    
                    
                    
            
            
            
            
            
        

                    
                    
          
        
        
        
            
            
                
                    
            
        
        
                
                    
                    
                    
            

        
            
            

            

                
                
                
                
            
        

        
        
            
            
                
                
        
        
        
                
            
        
        
        
        
        
            
            
        
                
                
                

        

                    
                
            

        
        
            
            
            
                
                
            
                
                
        

                
        
        

        
            
                
                
            
        
            
            
                
                

    

            
        
        
       
                
                    
                
            
            
        

            
            
                
            
            
        
                
        
                
                
            
        
            
                
                
                    
                
                
        
        


        
        
        
        

            
                    
            
                    
        
 

                
        
        

            
        
        
                
            
                
     
        
        
                
                
        
        
        
        
                
        

            
                
            


        
                
            
            
            
            
                    
        















    #<--Solving Area Ends
    endtime=datetime.datetime.now()
    time=(endtime-starttime).total_seconds()*1000
    if(os.path.exists('input.txt')):
        print("Time:",time,"ms")  
    
                
class FastReader(io.IOBase):
    newlines = 0

    def __init__(self, fd, chunk_size=1024 * 8):
        self._fd = fd
        self._chunk_size = chunk_size
        self.buffer = io.BytesIO()

    def read(self):
        while True:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, self._chunk_size))
            if not b:
                break
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines = 0
        return self.buffer.read()

    def readline(self, size=-1):
        while self.newlines == 0:
            b = os.read(self._fd, max(os.fstat(self._fd).st_size, self._chunk_size if size == -1 else size))
            self.newlines = b.count(b"\n") + (not b)
            ptr = self.buffer.tell()
            self.buffer.seek(0, 2), self.buffer.write(b), self.buffer.seek(ptr)
        self.newlines -= 1
        return self.buffer.readline()


class FastWriter(io.IOBase):

    def __init__(self, fd):
        self._fd = fd
        self.buffer = io.BytesIO()
        self.write = self.buffer.write

    def flush(self):
        os.write(self._fd, self.buffer.getvalue())
        self.buffer.truncate(0), self.buffer.seek(0)


class FastStdin(io.IOBase):
    def __init__(self, fd=0):
        self.buffer = FastReader(fd)
        self.read = lambda: self.buffer.read().decode("ascii")
        self.readline = lambda: self.buffer.readline().decode("ascii")


class FastStdout(io.IOBase):
    def __init__(self, fd=1):
        self.buffer = FastWriter(fd)
        self.write = lambda s: self.buffer.write(s.encode("ascii"))
        self.flush = self.buffer.flush


if __name__ == '__main__':
    sys.stdin = FastStdin()
    sys.stdout = FastStdout()
    main()







