Polycarpus loves lucky numbers. Everybody knows that lucky numbers are positive integers, whose decimal representation (without leading zeroes) contain only the lucky digits *x* and *y*. For example, if *x* = 4, and *y* = 7, then numbers 47, 744, 4 are lucky.

Let's call a positive integer *a* undoubtedly lucky, if there are such digits *x* and *y* (0 ≤ *x*, *y* ≤ 9), that the decimal representation of number *a* (without leading zeroes) contains only digits *x* and *y*.

Polycarpus has integer *n*. He wants to know how many positive integers that do not exceed *n*, are undoubtedly lucky. Help him, count this number.
The first line contains a single integer *n* (1 ≤ *n* ≤ 10<sup class="upper-index">9</sup>) — Polycarpus's number.
def columnas(m):
    matrixc=[]
    for i in range (0,len(m[0])):
        t=[]
        for row in m:
            t.append(row[i])
        matrixc.append(t)
    return matrixc
def straw(m):
    x=[]
    s="s"
    o=0
    for i in range (0,len(m)):
      if s not in m[i]:
        o+=len(m[i])
      else:
        x.append(m[i])
    r=columnas(x)
    for i in range (0,len(r)):
       if s not in (r[i]):
        o+=len(r[i])
    return o
rc=input()
rc=rc.split()
rc=[int(i) for i in rc]
m=[]
for i in range (0,rc[0]):
   data=input()
   data=data.split()
   m.append(data)
print (straw(m))
	 		  	  	  				    		  	 	  		