string_name=input()
s=0
flag=0
flagINT=-5
for element in range(0, len(string_name)):
    # IF CAPS
    if string_name[element].isupper():
        if flagINT != element-1:
            s = s + 1
            #print("+1 after 1 elem=", element)
            flagINT = element
        else:
            flagINT = element
        #if element==len(string_name) and flagINT==element-1:
        #    s = s - 1  

    # IF LOWER
    else:
        # (lower) AFTER CAPS
        if string_name[element-1].isupper() and element!=0:
            #print("+1 after 2 elem=", element)
            s = s + 1 
print(s)