#include <iostream>
#include <functional>
#include <algorithm>
#include <vector>
#include <numeric>
#include <utility>
#include <cmath>


#define WATCH(x) std::cout << (#x) << ": " << x << '\n';
#define xx(container, lambda) container.begin(), container.end(), lambda

using tt = std::vector<bool>;

struct Pair
{
	size_t index;
	bool token;
};

Pair check(const tt& in, int start)
{
	size_t end = start;
	bool token = in[start];
	bool prev = token;
	for (size_t i = start + 1; i < in.size(); i++)
	{
		if (in[i] == prev) { break; } 
		prev = in[i];
		end = i;
	}
	
	token = prev;	
	return {end, token};
}


void reverse(tt& in,size_t start, size_t end){

	std::reverse(in.begin() + start, in.begin() + end);
}

void print(tt& in){
	for(auto c: in)
		std::cout << (c?'+':'-');
	std::cout << std::endl;
}

size_t solve(tt in)
{	
	size_t operations = 0;
	
	size_t start = 0;
	while(start <= in.size()-1)
	{
			
		auto p = check(in, start);
		start = p.index;
		//WATCH(p.index)
		auto next = check(in,p.index+1);
		//WATCH(next.index)
		if(next.index == in.size())
		{
			break;

		}




		reverse(in, p.index +1, next.index +1 );
		
		start = next.index;
		
		++operations;
	}


//	print(in);
	return operations;
}

int main()
{
	std::string input;
	std::cin >> input;
	std::vector<bool> in(input.size());
	for (int i = 0; i < input.size(); i++) { in[i] = input[i] == '+'; }
	
	//WATCH(in.size())
	std::cout << solve(in) << '\n'; 

	return 0;
}