diff --git a/HDOJ/5912_Richard.cpp b/HDOJ/5912_Richard.cpp
new file mode 100644
index 0000000..fd1f0c8
--- /dev/null
+++ b/HDOJ/5912_Richard.cpp
@@ -0,0 +1,47 @@
+#include <iostream>
+#include <cstdio>
+#include <algorithm>
+#include <cstring>
+#include <string>
+
+using namespace std;
+
+long long gcd(long long x,long long y)
+{
+    return y?gcd(y,x%y):x;
+}
+
+int main()
+{
+    int t;
+    cin>>t;
+    for(int cases=1;cases<=t;cases++)
+    {
+        int n;
+        cin>>n;
+        long long a[20];
+        long long b[20];
+        for(int i=1;i<=n;i++)
+            cin>>a[i];
+        for(int i=1;i<=n;i++)
+            cin>>b[i];
+        long long fenzi=b[n];
+        long long fenmu=a[n];
+        long long fenzi2=fenzi;
+        long long fenmu2=fenmu;
+        for(int i=n-1;i>=1;i--)
+        {
+            fenzi2=b[i]*fenmu;
+            fenmu2=fenmu*a[i]+fenzi;
+            long long temp=gcd(fenzi2,fenmu2);
+            fenzi=fenzi2/temp;
+            fenmu=fenmu2/temp;
+        }
+        long long temp=gcd(fenzi2,fenmu2);
+        fenzi=fenzi2/temp;
+        fenmu=fenmu2/temp;
+        cout<<"Case #"<<cases<<": ";
+        cout<<fenzi<<" "<<fenmu<<endl;
+    }
+    return 0;
+}