diff --git a/src/main.rs b/src/main.rs
index 8c48057..167dde8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -27,8 +27,8 @@ impl Calc {
         self.display();
     }
     fn eval(&mut self) {
-        let left = self.left.parse::<u32>().unwrap();
-        let right = self.right.parse::<u32>().unwrap();
+        let left = self.left.parse::<u32>().unwrap_or(0);
+        let right = self.right.parse::<u32>().unwrap_or(0);
         let ans = match self.operator {
             Some(Operators::PLUS) => left + right,
             Some(Operators::MINUS) => left - right,