As Ruby to complete the array (hash) by the condition?

For example, there is an array:

list = [
{ 'name': 'Аntonello', num: 3 }
{ 'name': 'Sergello', num: 5 }
{ 'name': 'Аntonello', num: 3 }
]

Here are the first and third elements of the same name, and num. How can they pick on a new array of such data have already been a number of copies (with a new count field)?
I.e., in our case it should be array:

list = [
{ 'name': 'Аntonello', count: 2 }
{ 'name': 'Sergello', count: 1 }
]