diff --git a/HDOJ/1870.cpp b/HDOJ/1870.cpp
new file mode 100644
index 0000000..5d690e2
--- /dev/null
+++ b/HDOJ/1870.cpp
@@ -0,0 +1,21 @@
+#include <cstdlib>
+#include <cstdio>
+#include <cstring>
+using namespace std;
+
+char buffer[1024];
+int main()
+{
+    while(scanf("%s",buffer)==1)
+    {
+        int idt=strstr(buffer,"B")-buffer;
+        int cnt=0;
+        for(int i=idt-1;i>=0;i--)
+        {
+            if(buffer[i]=='(') cnt++;
+            else cnt--;
+        }
+        printf("%d\n",cnt);
+    }
+    return 0;
+}