#include<stdio.h>
#include<string.h>
int min(int a,int b)
{
if(a<b)
return(a);
else
return(b);
}
int main()
{
int t;
scanf("%d",&t);
while(t–)
{
int n,i,k,sum=0,ans=0,j,s;
char ar[100005];
scanf("%d%d",&n,&k);
for(i=1;i<=n;i++)
scanf(" %c",&ar[i]);
for(i=1;i<=n;i++)
{
if(ar[i]==‘R’)
{
ans++;
j=min(n,(i+k-1));
sum++;
s=i;
break;
}
}
s++;
for(i=s;i<=n;i++)
{
if(i<=j)
{
if(ar[i]=='G'&&sum%2!=0)
{
ans++;
j=min(n,(i+k-1));
sum++;
}
}
else
{
if(ar[i]=='R')
{
ans++;
j=min(n,(i+k-1));
sum++;
}
}
}
printf("%d\n",ans);
}
}