import std.stdio, std.conv, std.string, std.array, std.range, std.algorithm, std.container;
import std.math, std.random, std.bigint, std.datetime, std.format;
void main(string[] args){ if(args.length > 1) if(args[1] == "-debug") DEBUG = 1; solve(); }
void log()(){ writeln(""); } void log(T, A ...)(T t, lazy A a){ if(DEBUG) write(t, " "), log(a); } bool DEBUG = 0; 
string rstring(){ static string[] ss; while(!ss.length) ss = readln.chomp.split; string res = ss[0]; ss.popFront; return res; }
T rtype(T)(){ return rstring.to!T; } alias rint = rtype!int, rlong = rtype!long, rreal = rtype!real;
T[] rtypes(T)(int n){ return n.iota.map!(i => rtype!T()).array; } alias rint = rtypes!int, rlong = rtypes!long, rreal = rtypes!real;
T[][] rtypess(T)(int n, int m){ return n.iota.map!(i => rtypes!T(m)).array; } alias rint = rtypess!int, rlong = rtypess!long, rreal = rtypess!real;

// ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- ----- //

void solve(){
	string s = rstring;
	long k = rlong;
	long n = s.length;
	
	bool f = 0;
	long ans;
	
	foreach(i; 0 .. n){
		if(f > 0){
			f = 0;
			continue;
		}
		else{
			if(i > 0 && s[i - 1] == s[i]){
				f = 1;
				ans += (k + 1) / 2;
			}
		}
	}
	log("ans:", ans);
	
	if(f > 0){
		f = 0;
	}
	else{
		if(s[n - 1] == s[0]){
			f = 1;
			ans += k / 2;
		}
	}
	log("ans:", ans);
	
	foreach(i; 1 .. n){
		if(f > 0){
			f = 0;
			continue;
		}
		else{
			if(i > 0 && s[i - 1] == s[i]){
				f = 1;
				ans += k - (k + 1) / 2;
			}
		}
	}
	log("ans:", ans);
	
	if(f > 0){
		f = 0;
	}
	else{
		if(s[n - 1] == s[0]){
			f = 1;
			ans += (k - 1) - k / 2;
		}
	}
	log("ans:", ans);
	
	ans.writeln;
}
