def oi(): return int(input())
def os(): return input()
def mi(): return list(map(int, input().split()))

# import sys
# input = sys.stdin.readline
# import sys
# sys.setrecursionlimit(10**8)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')
input_count = 0

input_count = 0
oi()
S = os()
ans = S.count("#")*2
if S[-1]=="#":
    ans -= 1
print(ans)