scheduling_2

tasks = [int(n) for n in input().split(', ')]
indx = int(input())

total_time = 0
needed_task = tasks[indx]
tasks_dict = {idx: value for idx, value in enumerate(tasks)}

sorted_tasks = sorted(tasks_dict.items(), key=lambda kvp: (kvp[1], kvp[0]))
for index, value in sorted_tasks:
    if (value < needed_task) or (value == needed_task and index <= indx):
        total_time += value
    else:
        break
print(total_time)