def find_missing(input_list):
 total = ((len(input_list) * (len(input_list) + 1)) / 2)
 summed = 0
 for element in input_list:
  summed += element
 missing = (total - summed)
 return missing

def find_missing ( input_list ) : total = ( ( len ( input_list ) * ( len ( input_list ) + 1 ) ) / 2 ) summed = 0 for element in input_list : summed += element missing = ( total - summed ) return missing
find the missing number in shuffled list .