myBook = {

"tsans@gmail.com": {
    "first": "Thierry",
    "last": "Sans",
    "mobile": "+974 1111 1111",
    "office": "+974 2222 2222",
    "home": "+974 3333 3333",
},

"msmahmou@qatar.cmu.edu":{
    "first":"Mohammad",
    "last": "Mahmoud",
    "home": "+974 7777 7777",
},

"memadi@qatar.cmu.edu":{
    "first":"Mohammad",
    "last":"Emadi",
    "office":"+974 8888 8888",
},

"skhirawi@gmail.com":{
    "first":"Sarah",
    "last":"Khirawi",
    "mobile":"+974 6666 6666"
},

}

print myBook["tsans@gmail.com"]["mobile"]



