N = int(input())
S = input().strip()
for i in range(N):
    if S[i]=="#":
        ind = i
        break
S = S[ind:]
N = len(S)
ans = 0
for i in range(N-1,-1,-1):
    if S[i]=="#":
        j = i
        break
n1 = 0
n0 = 0
for i in range(j,-1,-1):
    if S[i]=="#" and n0==0:
        n1 += 1
    elif S[i]=="#" and n0>0:
        ans += max(n1-n0,0)
        n0 = 0
        n1 = 1
    elif S[i]=="." and n1>0:
        n0 += 1
ans += n1-1+N
print(ans)