diff --git a/PATBasic/1091.c b/PATBasic/1091.c
new file mode 100644
index 0000000..48c7abb
--- /dev/null
+++ b/PATBasic/1091.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+
+int main()
+{
+    int M, N, K, L, mask;
+
+    scanf("%d", &M);
+    for(int i = 0; i < M; i++)
+    {
+        scanf("%d", &K);
+        for(N = 1; N < 10; N++)
+        {
+            L = N * K * K;
+
+            /* compare the lowest digits one by one */
+            for(mask = 1; mask <= K; mask *= 10)
+                if(L / mask % 10 != K / mask % 10)
+                    break;
+
+            if(mask > K)  /* all passed! */
+            {
+                printf("%d %d\n", N, L);
+                break;
+            }
+        }
+        if(N == 10)  /* No results */
+            printf("No\n");
+    }
+
+    return 0;
+}
diff --git a/PATBasic/1092.c b/PATBasic/1092.c
new file mode 100644
index 0000000..7a36f24
--- /dev/null
+++ b/PATBasic/1092.c
@@ -0,0 +1,29 @@
+#include <stdio.h>
+
+int main()
+{
+    int N, M, cur, max = 0, sales[1000] = {0};
+
+    scanf("%d %d", &N, &M);
+    for(int i = 0; i < M; i++)
+    {
+        for(int j = 0; j < N; j++)
+        {
+            scanf("%d", &cur);
+            sales[j] += cur;
+        }
+    }
+
+    /* find the max */
+    for(int i = 0; i < N; i++)
+        if(max < sales[i])
+            max = sales[i];
+
+    /* print all the indexes of max sales */
+    printf("%d", max);
+    for(int i = 0, count = 0; i < N; i++)
+        if(sales[i] == max)
+            printf("%c%d", count++ ? ' ' : '\n', i + 1);
+
+    return 0;
+}
diff --git a/PATBasic/1093.c b/PATBasic/1093.c
new file mode 100644
index 0000000..651460b
--- /dev/null
+++ b/PATBasic/1093.c
@@ -0,0 +1,21 @@
+#include <stdio.h>
+
+int main()
+{
+    char c;
+    int lines = 0, ascii[128] = {0};
+
+    while(lines < 2)
+    {
+        c = getchar();
+        if(c == '\n')
+            lines++;
+        else if(!ascii[(int)c])
+        {
+            putchar(c);
+            ascii[(int)c]++;
+        }
+    }
+
+    return 0;
+}
diff --git a/PATBasic/1094.c b/PATBasic/1094.c
new file mode 100644
index 0000000..a8f8f14
--- /dev/null
+++ b/PATBasic/1094.c
@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int iPrime(int n)
+{
+    if(n < 2)
+        return 0;
+    for(int i = 2; i * i <= n; i++)
+        if(n % i == 0)
+            return 0;
+    return 1;
+}
+
+int main()
+{
+    char N[1000], n[10] = {0};
+    int L, K;
+
+    scanf("%d %d %s", &L, &K, N);  /* L == strlen(N) */
+    for(int i = 0; i <= L - K; i++)
+    {
+        strncpy(n, N + i, K);
+        if(iPrime(atoi(n)))
+        {
+            printf("%s", n);
+            return 0;
+        }
+    }
+
+    printf("404");
+    return 0;
+}