create a function of a set of integers and a value for which you need to find the nearest one.

def find_closest(lst, K): 
    return lst[min(range(len(lst)), key = lambda i: abs(lst[i]-K))] 
  
# Driver code 
lst = [4, 7, 10, 11, 12, 17] 
K = 13
print(find_closest(lst, K))