next_round

n = input()
a = n[0]
b = n[2]
list = []
count1 = 0
for i in range(int(a)):
    list.append(int(input())) 
for j in range(len(list)):
    if list[j] == 0:
        count1= count1 + 1
list1 = list[int(b): ]
n = list1.count(list[int(b)])           
count = len(list[0:int(b)]) + n - count1
print(count)