text: def firstNR(arr, n): 
    
  	for i in range(n): 
  		j = 0
  		while(j < n): 
  			if (i != j and arr[i] == arr[j]): 
  				break
  			j += 1
  		if (j == n): 
  			return arr[i] 
  	
  	return -1
  	
  # Driver code
  n=raw_input('Enter size : ')
  arr=[]
  for i in range(0,n):
    arr.append(input('enter element'))
  print(firstNR(arr, n))
  