#include <iostream>
#include <deque>
using namespace std;
 
int main(){
	deque<int> folder;
    unsigned long long N;
    
    cin >> N;
    folder.push_back(N%10);
	N/=10;
	while (N!=0){
		for (int i=0; i<folder.size(); i++){
			if (folder.at(i) == N%10)
				i+=folder.size();	
			if (i == folder.size() -1)
				folder.push_back(N%10);
		}
        N/=10;
    }
 	cout << "sum:" << folder.size();
 
    return 0;
}