diff --git "a/Retos/Reto #28 - EXPRESI\303\223N MATEM\303\201TICA [Media]/java/EspinoLeandroo.java" "b/Retos/Reto #28 - EXPRESI\303\223N MATEM\303\201TICA [Media]/java/EspinoLeandroo.java"
new file mode 100644
index 0000000000..87028c7c54
--- /dev/null
+++ "b/Retos/Reto #28 - EXPRESI\303\223N MATEM\303\201TICA [Media]/java/EspinoLeandroo.java"	
@@ -0,0 +1,45 @@
+public class EspinoLeandroo {
+
+    public static void main(String[] args) {
+        String expression1 = "5 + 16 / 7 - 4";
+        String expression2 = "5 a 6";
+
+        System.out.println(validateMathExpression(expression1)); 
+        System.out.println(validateMathExpression(expression2)); 
+    }
+
+    public static boolean validateMathExpression(String expression) {
+        String[] tokens = expression.split("\\s+");
+        
+        if (tokens.length % 2 == 0) {
+            return false;
+        }
+
+        for (int i = 0; i < tokens.length; i++) {
+            if (i % 2 == 0) {
+                if (!isNumber(tokens[i])) {
+                    return false;
+                }
+            } else { 
+                if (!isOperation(tokens[i])) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
+    private static boolean isNumber(String token) {
+        try {
+            Double.parseDouble(token);
+            return true;
+        } catch (NumberFormatException e) {
+            return false;
+        }
+    }
+
+    private static boolean isOperation(String token) {
+        return token.matches("[+\\-*/%]");
+    }
+}