#include <stdio.h>#include <string.h>#define N 50#define M 10int n, m, ok, vis[N];int list[M][N], cnt[M], map[M][M];int rec[M][M];struct puzzle{ int top; int right; int bottom; int lift;}block[N];int change_char(char c){ if (c == 'F')return 0; else if (c == 'O')return 1; else if (c == 'I')return 2;}bool judge(){ rec[0][3] = m; rec[1][3] = n; for (int i = 0; i < 2; i++){if (rec[i][0] != rec[3 - i][0] || rec[i][0] != rec[i][3]) return false;//if (rec[i][1] + rec[i][2] != rec[i][3])// return false;for (int j = 1; j <= 2; j++) if (rec[i][j] != rec[3 - i][3 - j])return false; }// printf("!n"); return true;}void handle(int cur, char str[]){ int p, q, k, t; p = block[cur].top = change_char(str[0]); rec[0][p]++; k = block[cur].right = change_char(str[1]); rec[1][k]++; t = block[cur].bottom = change_char(str[2]); rec[3][t]++; q = block[cur].lift = change_char(str[3]); rec[2][q]++; list [p * 3 + q][cnt[p * 3 + q]++] = cur;}int change_num(int x, int y){ int k = 0; if (x == 2)k += 1; else if (x == 1)k += 2; if (y == 2)k += 3; else if (y == 1)k += 6; return k;}void dfs(int x, int y){ int cur = change_num(block[map[x][y - 1]].right, block[map[x - 1][y]].bottom); for (int i = 0; i < cnt[cur]; i++){if (vis[list[cur][i]]) continue;if (x == n && y == m){ if (block[list[cur][i]].right + block[list[cur][i]].bottom)continue; ok = 1; return;}else if (x == n){ if (block[list[cur][i]].right == 0 || block[list[cur][i]].bottom)continue; vis[list[cur][i]] = 1; map[x][y] = list[cur][i]; dfs(x, y + 1);}else if (y == m){ if (block[list[cur][i]].right || block[list[cur][i]].bottom == 0)continue; vis[list[cur][i]] = 1; map[x][y] = list[cur][i]; dfs(x + 1, 1);}else{ if (block[list[cur][i]].right == 0 || block[list[cur][i]].bottom == 0)continue; vis[list[cur][i]] = 1; map[x][y] = list[cur][i]; dfs(x, y + 1);}vis[list[cur][i]] = 0;if (ok) return; }}int main(){ char str[M]; while (scanf("%d%d", &n, &m), n + m){// Init.memset(block, 0, sizeof(block));memset(list, 0, sizeof(list));memset(vis, 0, sizeof(vis));memset(cnt, 0, sizeof(cnt));memset(map, 0, sizeof(map));memset(rec, 0, sizeof(rec));ok = 0;// Read.for (int i = 1; i <= n * m; i++){ scanf("%s", str); handle(i, str);}if (judge()) dfs(1, 1);printf("%sn", ok?"YES":"NO"); } return 0;}
