7 1
NNFFFNN

#include<bits/stdc++.h>
#define ll long long
#define N 100010
#define fsb(a,b,c) for(int a=b;a<=c;a++)
#define fbs(a,b,c) for(int a=b;a>=c;a--)
using namespace std;
int n,m,a[N],l,r,mid,b[N],cnt=0;
char s[N];
inline void work(){
 int last=2;
 fsb(i,1,n)
  if(a[i]!=last){
   b[++cnt]=1;last=a[i];
  }else b[cnt]++;
}
inline int check(int x){
 int cnt1=0;
 fsb(i,1,cnt)cnt1+=b[i]/(x+1);
 return cnt1<=m; 
}
int main(){
 scanf("%d%d",&n,&m);scanf("%s",s+1);
 fsb(i,1,n)a[i]=s[i]=='N'?1:0;
 work();
 int cnt2=0;
 fsb(i,1,n){
  if(a[i]+(i&1)==1)cnt2++;
 }
 if(cnt2<=m||n-cnt2<=m){
  puts("1");return 0; 
 }
 l=2;r=n;
 while(l+5<r){
  mid=(l+r)>>1;
  if(check(mid))r=mid;else l=mid;
 }
 fsb(i,l,r)if(check(i)){
  printf("%d\n",i);return 0;
 }
 return 0;
}