#include <iostream>

using namespace std;

struct brTree {
    char data;
    brTree *lchild;
    brTree *rchild;
};

void creatTree(brTree *&tree)
{
    char c;
    cin >> c;
    if (c == '#')
    {
        tree = NULL;
    }
    else
    {
        tree = new brTree;
        tree->data = c;
        creatTree(tree->lchild);
        creatTree(tree->rchild);
    }
}


void getTree(brTree *tree, int &count)
{
    if (tree == NULL)
    {
        return;
    }
    if (tree->rchild != NULL)
    {
        count++;
        getTree(tree->rchild, count);
    }
}

int maxcount = 0;

void gedDegree(brTree *tree, int Count)
{
    if (tree == NULL)
    {
        return;
    }

    if (tree->rchild)
    {
        gedDegree(tree->rchild, Count + 1);
    }
    else
    {
        if (Count > maxcount)
        {
            maxcount = Count;
        }
    }

    if (tree->lchild)
    {
        gedDegree(tree->lchild, 0);
    }

}


int max = 0;
int main()
{
    brTree *tree = NULL;
    creatTree(tree);

    if (tree->rchild != NULL)
    {
        cout << "ERROR";
    }
    else
    {
        gedDegree(tree, 0);
        cout << maxcount + 1;
    }

    return 0;
}