diff --git a/src/kr/kr_1-1_sum.c b/src/kr/kr_1-1_sum.c
new file mode 100644
index 0000000..0592cd3
--- /dev/null
+++ b/src/kr/kr_1-1_sum.c
@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <string.h>
+
+#define MAX_SIZE 100
+
+
+int main(void)
+{
+    int sizeNumbers = 6;
+    int numbers[6] = {10,20,30,49,50,60};
+
+    int maxSum = 0;
+    int maxSumInd[6] = {0};
+    for (int i = 0; i < sizeNumbers; i++) {
+        int sum = (numbers[i] / 10) + (numbers[i] - ((numbers[i] / 10) * 10)); 
+        //printf("%d\n", sum);
+        if (sum > maxSum) {
+            maxSum = sum;
+            for (int j = 0; j < sizeNumbers ;j++)
+                maxSumInd[j] = 0;
+            maxSumInd[i] = 1;
+        } else if (sum == maxSum) {
+            maxSumInd[i] = 1;
+        }
+    }
+    for (int i = 0; i < sizeNumbers; i++) {
+        if (maxSumInd[i] == 1) {
+            printf("%d\n", numbers[i]);
+            return 0;
+        }
+    }
+    return -1;
+}
diff --git a/src/kr/kr_1-3_palindrom.c b/src/kr/kr_1-3_palindrom.c
new file mode 100644
index 0000000..c3c89e6
--- /dev/null
+++ b/src/kr/kr_1-3_palindrom.c
@@ -0,0 +1,40 @@
+#include <string.h>
+#include <stdio.h>
+#define MAX_SIZE 100
+
+int isPal(int num) {
+    char binNum[MAX_SIZE];
+    int count = 0;
+    while (num > 0) {
+        if (num % 2 == 1) {
+            num = num / 2;
+            binNum[count] = 1;
+        } else {
+            num = num / 2;
+            binNum[count] = 0;
+        }
+
+        //printf("%d", binNum[count]);
+        count = count + 1;
+    }
+
+    for (int i = 0; i <= count; i++) {
+        if (binNum[i] == binNum[count - i])
+            return 0;
+    }
+
+    return 1;
+}
+
+
+int main(void)
+{
+    int n;
+    scanf("%d", &n);
+    for (int i = 1; i <= n; i++) {
+        int result = isPal(i);
+        if (result == 1)
+            printf("%d\n", i);
+    }
+    return 0;
+}