题解 | #小苯的Z串匹配#

T = int(input().strip())
ans = []
def calu(a,s,cnt):
    for i in range(len(a)):
        if s[i]=='>':
            if a[i] <= 0:
                cnt += 1
                a[i] = 1

        elif s[i]=='<':
            if a[i] >= 0:
                cnt += 1
                a[i] = -1

        else:
            if a[i-1] * a[i] <= 0:
               a[i] = -a[i-1]
               cnt += 1

    return cnt
for j in range(T):
    n = int(input().strip())
    a = list(map(int,input().split()))
    s = input().strip()
    ans.append(calu(a,s,0))

for k in ans:
    print(k)