S = input()
i,k = 0,[0]
ik = 0
Ans = 0
for a in range(len(S)):
    if S[a] == ">":
        if ik != 2:
            Ans += 1
            ik = 0
        else:
            i -= 1
            k.pop(-1)
    elif S[a] == "<":
        k.append(0)
        i += 1
        ik = 1
    else:
        k[-1] += 1
        if ik == 1:
            ik = 2
Ans += i+sum(k)


        
print(Ans)