A. Anton and Letters

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket
at the end of the line.

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed,
separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Sample test(s)

input

{a, b, c}

output

3

input

{b, a, b, a}

output

2

input

{}

output

0

解题说明：此题事实上就是考察C++中的set，把输入处理好就可以。

#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include <set>
using namespace std;

int main()
{
	string s;
	set<char> t;
	while (cin>>s)
	{
		if (s[0]!='{')
		{
			t.insert(s[0]);
		}
		else if (s[1]!='}')
		{
			t.insert(s[1]);
		}
	}
	cout<<t.size()<<endl;
	return 0;
}