diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..a1720fc
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+# Build go binary
+
+frog
\ No newline at end of file
diff --git a/README.md b/README.md
index fda46c1..7e6cc56 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,8 @@
 # frog_problem
 Here is the frog problem code I wrote in an Edinburgh pub.
 
-Feel free to make better version. This one has not changed since I wrote it. V1 was the same code but saved before I changed it to work for different distances so I have not bothered upload it as well (it was still very unifinished).
+Feel free to make better version. This one has not changed since I wrote it. V1
+was the same code but saved before I changed it to work for different distances
+so I have not bothered upload it as well (it was still very unifinished).
 
-Video is here: https://youtu.be/ZLTyX4zL2Fc
+Video is here: https://youtu.be/ZLTyX4zL2Fc
\ No newline at end of file
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..ea5fc00
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/standupmaths/frog
+
+go 1.12
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..10b03c8
--- /dev/null
+++ b/main.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"math/big"
+	"os"
+	"strconv"
+)
+
+func main() {
+	// Parse input value from command line args.  Do simple validation.
+	n := 10
+	if len(os.Args) > 1 {
+		parsed, err := strconv.ParseInt(os.Args[1], 10, 64)
+		if err != nil || parsed < 1 {
+			panic("Input target must be a positive integer")
+		}
+		n = int(parsed)
+	}
+
+	sum := big.NewRat(0, 1)
+
+	for i := 1; i <= n; i++ {
+		sum = sum.Add(sum, big.NewRat(1, int64(i)))
+	}
+
+	fmt.Printf("Frog(%d) = %s == %s\n", n, sum.String(), sum.FloatString(10))
+}