diff --git a/buggy.py b/buggy.py
--- a/buggy.py
+++ b/buggy.py
@@ -2,7 +2,7 @@
 
 N = int(input())
 S = list(input())
-mod = 998244353
+mod = 10**9 + 7
 for i in range(0, N, 2):
     if S[i] == "A":
         S[i] = "B"
