candy_list =list(map(str,input()))
candy_len = len(candy_list)
for i in range(0,candy_len):
    if(i==0):
        i+=1
    else:
        if(i<candy_len-1):
            if(candy_list[i]==candy_list[i-1]):
                print(i)
                break
            else:
                i+=1
        else:
            print(candy_len)