diff --git a/c04_string/input.c b/c04_string/input.c
new file mode 100644
index 0000000..b810ea2
--- /dev/null
+++ b/c04_string/input.c
@@ -0,0 +1,16 @@
+/* input.c - 何时使用& */
+#include <stdio.h>
+
+int main(void)
+{
+    int age;
+    float assets;
+    char pet[30];
+
+    printf("Enter your age, assets, and favorite pet.\n");
+    scanf("%d %f", &age, &assets);
+    scanf("%s", pet);
+    printf("%d $%.2f %s\n", age, assets, pet);
+    
+    return 0;
+}
\ No newline at end of file