How to import addresses into Bitcoin client

1,"1DdDMWFX3h6fkjktDBsKuUN91vVz8KpMnB","L33oVzrKNfwWHxPubNc9MGuYLxGmJFCQdgibV1oFCEq3tPPQapvz"
2,"15o6KpFLdFkVGkoZLEJPcZt7AaWLR5ZAsm","L3iTwmNdRborLifKWNJzYagsiPcEdvcMKCGeAgPCZ2XzMUrzdkyb"

I generated two addresses, how can I add them to the client?

Security Note: Do NOT use the addresses you pasted in your question. Anyone can now access any funds in those addresses as anyone can import the private keys and gain full access to the addresses, including sending the BTC.

It will depend on the client you use. Here are two examples:

Electrum:

1. Start a new wallet file
2. When given the option to select what kind of wallet to use, select Import Bitcoin addresses or private keys
3. Paste your private keys here
4. Complete the setup to gain access to the funds

Bitcoin Core:

1. Open your wallet
2. Click Window -> Console
3. If you have protected your wallet, use this command walletpassphrase "YourLongPassphrase" 600
4. Use this command to import private keys importprivkey yourPrivateKeyInWalletImportFormat