diff --git a/PKU/1087 - A Pluf for UNIX.cpp b/PKU/1087 - A Plug for UNIX.cpp
similarity index 100%
rename from PKU/1087 - A Pluf for UNIX.cpp
rename to PKU/1087 - A Plug for UNIX.cpp
diff --git a/Tianjin Online Judge/1679 - Hidden Password.cpp b/Tianjin Online Judge/1679 - Hidden Password.cpp
new file mode 100644
index 0000000..1b0316b
--- /dev/null
+++ b/Tianjin Online Judge/1679 - Hidden Password.cpp	
@@ -0,0 +1,34 @@
+#include <cstdio>
+#include <cstring>
+#include <algorithm>
+
+using namespace std;
+
+int main(){
+	int T,L;
+	char s[100001];
+	
+	scanf("%d",&T);
+	
+	while(T--){
+		scanf("%d %s",&L,s);	
+	
+		int ans = 0,p = 1,l = 0;
+	
+		while(p<L && ans+l+1<L){
+			if(s[ans+l]==s[(p+l)%L]) ++l;
+			else if(s[ans+l]<s[(p+l)%L]){
+				p = p+l+1;
+				l = 0;
+			}else{
+				ans = max(ans+l+1,p);
+				p = ans+1;
+				l = 0;
+			}
+		}
+	
+		printf("%d\n",ans);
+	}
+	
+	return 0;
+}