unsigned int a;
It can be useful in these situations to use typedef, which enables you to create aliases to any of the usual C++ datatypes. For example:
typdef unsigned int UnsignedInt;
In this example we have created an alias called UnsignedInt which we can then use to declare variables of type unsigned int.
Another example, this time using char:
typedef char field;
Here we have created an alias called field which can be used to declare variables of type char.