diff --git a/contracts/common.sol b/contracts/common.sol
new file mode 100644
index 0000000..17f2ba9
--- /dev/null
+++ b/contracts/common.sol
@@ -0,0 +1,61 @@
+pragma solidity ^0.6.0;
+
+interface MemoryInterface {
+    function getUint(uint _id) external returns (uint _num);
+    function setUint(uint _id, uint _val) external;
+}
+
+interface EventInterface {
+    function emitEvent(uint _connectorType, uint _connectorID, bytes32 _eventCode, bytes calldata _eventData) external;
+}
+
+
+contract Memory {
+
+    /**
+     * @dev ETH Address.
+     */
+    function getEthAddr() public pure returns (address) {
+        return 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
+    }
+
+    /**
+     * @dev Return InstaMemory Address.
+     */
+    function getMemoryAddr() public pure returns (address) {
+        return 0x8a5419CfC711B2343c17a6ABf4B2bAFaBb06957F; // InstaMemory Address
+    }
+
+    /**
+     * @dev Return InstaEvent Address.
+     */
+    function getEventAddr() public pure returns (address) {
+        return 0x2af7ea6Cb911035f3eb1ED895Cb6692C39ecbA97; // InstaEvent Address
+    }
+
+    /**
+     * @dev Get Stored Uint Value From InstaMemory.
+     * @param getId Storage ID.
+     * @param val if any value.
+     */
+    function getUint(uint getId, uint val) internal returns (uint returnVal) {
+        returnVal = getId == 0 ? val : MemoryInterface(getMemoryAddr()).getUint(getId);
+    }
+
+    /**
+     * @dev Store Uint Value In InstaMemory.
+     * @param setId Storage ID.
+     * @param val Value To store.
+     */
+    function setUint(uint setId, uint val) internal {
+        if (setId != 0) MemoryInterface(getMemoryAddr()).setUint(setId, val);
+    }
+
+    /**
+     * @dev Connector ID and Type.
+     */
+    function connectorID() public pure returns(uint _type, uint _id) {
+        (_type, _id) = (1, 2);
+    }
+
+}
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