S=input();N=len(S)

X={(0,0)}
u,d,l,r="a","*","b","c"
x=y=0

for s in S:
    if (x+y)%2==0:
        if s==u:
            y+=1
            u,d=d,u
        elif s==l:
            x-=1
            u,d,l,r="*",r,u,l
        elif s==r:
            x+=1
            u,d,l,r="*",l,r,u
    else:
        if s==d:
            y-=1
            u,d=d,u
        elif s==l:
            x-=1
            u,d,l,r=r,"*",d,l
        elif s==r:
            x+=1
            u,d,l,r=l,"*",r,d
    X.add((x,y))
print(len(X))