diff --git a/E_1572_MatrixDiagonalSum.java b/E_1572_MatrixDiagonalSum.java
new file mode 100644
index 0000000..04ee48e
--- /dev/null
+++ b/E_1572_MatrixDiagonalSum.java
@@ -0,0 +1,10 @@
+class Solution {
+    public int diagonalSum(int[][] mat) {
+        int ret = 0;
+        for (int i=0; i<mat.length; i++) {
+            ret += mat[i][i]; 
+            ret += mat[mat.length-1-i][i]; 
+        }
+        return (mat.length%2==0) ? ret : ret-mat[mat.length/2][mat.length/2]; 
+    }
+}
\ No newline at end of file