Read the following letter and answer the given question.

Dear Sam,

How are you? It’s been long since we met. I hope you’re doing great.

As winters are approaching, I was thinking to spend some time with you. I really miss our school days when we used to hang out together all day long. Remember eating those spicy corn bhajjis at Chandni Chowk? I haven’t been there since you shifted to Mumbai. I feel like going back to the past sometimes. Nevertheless, I was thinking if we could spend the winter breaks together at my place in Delhi. We will visit all those places we used to, meet our school time friends. To add the cherry on the cake, we could also visit Rishikesh or Dehradun, if possible.I am excited at the thought of meeting you, Sam. I have got a long list of things ready to tell you. Hope, you’d feel the same way. Give my regards to uncle and aunty.

Hope to hear a YES from you this time!

Your buddy,

 Nico

According to the letter, where has Sam shifted to?