！？青青？！，！？水水？！

#include<bits/stdc++.h>
using namespace std;
#define int long long
const int N=2e5+10;
int a[N],b[N],s[N];char st[N];
signed main()
{
	int n,m=0,k;cin>>st+1>>k;n=strlen(st+1);
	for(int i=1;i<=n;i++)if(st[i]=='Y')b[++m]=i;
	for(int i=1;i<=m;i++)s[i]=s[i-1]+b[i];
	int l=0,r=m,res=0;
	while(l<=r)
	{
		int mid=(l+r)>>1,bk=0;
		for(int i=mid;i<=m;i++)
		{
			int sum=s[i]-s[i-mid/2]-(s[i-mid+mid/2]-s[i-mid])-(mid/2)*(mid/2+1)/2-((mid-1)/2)*((mid-1)/2+1)/2;
			if(sum<=k)
			{
				bk=1;
				break;
			}
		}
		if(bk)l=mid+1,res=mid;
		else r=mid-1;
	}
	cout<<res<<'\n';
	return 0;
}