def verific(numar,numberOfFractions):
    nuExista = True
    for i in range(len(numberOfFractions)):
        if(numar == numberOfFractions[i]):
            nuExista = False
    return nuExista

with open("fractii.in",'r') as f:
    n = int(f.readline())

nr = 0
numberOfFractions = []
for i in range(1,n+1):
    for j in range(1,n+1):
      if verific(float(i / j), numberOfFractions):
          print(str(i)+'/'+str(j))
          nr += 1
          numberOfFractions.append(float(i / j))


with open("fractii.out",'w') as f:
    f.write(str(nr))