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| #include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
const int M = 2e6 + 10;
const int inf = 0x3f3f3f3f;
int n, k, s, t;
int cnt = 1;
int head[N];
struct edge {
int u, v, c, nxt;
edge(int u = 0, int v = 0, int c = 0, int nxt = 0) : u(u), v(v), c(c), nxt(nxt) {}
} e[M * 2];
void ADD(int u, int v, int c) {
cnt++;
e[cnt] = edge(u, v, c, head[u]);
head[u] = cnt;
}
void add_edge(int u, int v, int c) {
ADD(u, v, c);
ADD(v, u, 0);
}
int dep[N];
int now[N];
bool bfs() {
memset(dep, 0, sizeof dep);
memcpy(now, head, sizeof head);
queue<int>q;
dep[s] = 1;
q.push(s);
while (!q.empty()) {
int u = q.front();
q.pop();
for (int i = head[u]; i; i = e[i].nxt) {
int v = e[i].v;
int c = e[i].c;
if (dep[v] != 0 || !c) continue;
dep[v] = dep[u] + 1;
q.push(v);
}
}
return dep[t] != 0;
}
int dfs(int u, int t, int flow) {
if (u == t) return flow;
int nowflow = 0;
for (int i = now[u]; i; i = e[i].nxt) {
now[u] = i;
int v = e[i].v;
int c = e[i].c;
if (dep[v] != dep[u] + 1 || !c ) continue;
int ff = dfs(v, t, min(flow, c));
if (ff) flow -= ff, nowflow += ff, e[i].c -= ff, e[i ^ 1].c += ff;
}
return nowflow;
}
bool maxflow() {
int mxflow = 0;
int nowflow;
while (bfs()) {
while ((nowflow = dfs(s, t, inf))) mxflow += nowflow;
if (mxflow >= n) return 1;
}
return 0;
}
int re1[N];
int re2[N];
int main() {
cin >> n >> k;
s = n * 4 + 1, t = n * 4 + 2;
for (int i = 1; i <= n; i++) {
add_edge(i, n * 2 + i, k);
add_edge(n * 3 + i, n + i, k);
string a;
cin >> a;
for (int j = 0; j < n; j++) {
if (a[j] == 'Y') add_edge(i, j + 1 + n, 1);
else add_edge(n * 2 + i, j + 1 + n*3, 1);
}
}
int tot = 0;
for (int i = 1; i <= n; i++) add_edge(s, i, 1), re1[i] = cnt - 1, add_edge(i + n, t, 1), re2[i] = cnt - 1;
while (maxflow()) {
tot++;
for (int i = 1; i <= n; i++) {
e[re1[i]].c += e[re1[i] ^ 1].c;
e[re1[i] ^ 1].c = 0;
e[re2[i]].c += e[re2[i] ^ 1].c;
e[re2[i] ^ 1].c = 0;
}
}
cout << tot;
}
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