#include<bits/stdc++.h>
using namespace std;
string s;
set<int>x;
int t,ans;
inline int solve(string ss){
	int sum=0;
	for(int i=1;i<=min(s.size(),ss.size());i++){
		if(s[i-1]==ss[i-1]){
			sum++;
		}else return sum;
	}
}
void dfs(string s,int res){
	if(s.size()==t)return;
	for(int i=1;i<=26;i++){
		if(x.find(i)==x.end())continue;
		string ss=char('a'+i-1)+s;
		dfs(ss,res+solve(ss));
	}
}
int main(){
	freopen("string.in","r",stdin);
	freopen("string.out","w",stdout);
	cin>>s>>t;
	for(int i=0;i<s.size();i++)x.insert(s[i]-'a'+1);
	dfs("",0);
	cout<<ans;
	return 0;
}