def conversion(unit1):

if(unit1 ==1):

hectare(num)

if(unit2 ==2):

acre(num)

if(unit3 ==3):

squarekilometer(num)

measurement(unit1):

def hectare(num):

sq_ft1 = num * 107639

return(sq_ft1)

def acre(num):

sq_ft2 = num * 43560

return(sq_ft2)

def squarekilometer(num):

sq_ft3 = num * 1.076e+7

return(sq_ft3)