added programs

programs/prog3/info.json

@@ -0,0 +1,9 @@
+{
+    "name": "演習1ー8",
+    "description": "プロンプトから読み込んだ2つの整数値の積を表示するプログラム。",
+    "output": {
+        "type": "screenshot",
+	"content": "./assets/prog3.png"
+    },
+    "note": ""
+}

programs/prog3/main.c

@@ -0,0 +1,16 @@
+#include <stdio.h>
+
+int main(void) {
+    int n1;
+    int n2;
+
+    printf("Input two integers.\n");
+    printf("Integer n1: ");
+    scanf("%d", &n1);
+    printf("Integer n2: ");
+    scanf("%d", &n2);
+
+    printf("The product of two integers is %d.", n1 * n2);
+
+    return 0;
+}