diff --git a/subjects/foldint/main.go b/subjects/foldint/main.go
index a0f0c53e..0b5f13a5 100644
--- a/subjects/foldint/main.go
+++ b/subjects/foldint/main.go
@@ -18,3 +18,15 @@ func main() {
 	piscine.FoldInt(Mul, table, ac)
 	piscine.FoldInt(Sub, table, ac)
 }
+
+func Add(a, b int) int {
+	return a + b
+}
+
+func Mul(a, b int) int {
+	return a * b
+}
+
+func Sub(a, b int) int {
+	return a - b
+}