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
            Ans += i
            i = 0
        else:
            i -= 1
            k.pop(-1)
            if i >= 1:
                if k[-1] != 0:
                    ik = 2
                else:
                    ik = 1
            else:
                ik = 0

    elif S[a] == "<":
        k.append(0)
        i += 1
        ik = 1
    elif S[a] == "=":
        if ik >= 1:
            k[-1] += 1
            ik = 2
        else:
            Ans += 1
    #print(i,k,ik,Ans)
    
    
    
Ans += i+sum(k)


        
print(Ans)