In[]:= a=RandomInteger[(2^62)-1]
Out[]= 1679813589618336900

In[]:= b=RandomInteger[(2^62)-1]
Out[]= 1648532086516099370

In[]:= c=RandomInteger[(2^62)-1]
Out[]= 431124923357188627

In[]:= d=RandomInteger[(2^62)-1]
Out[]= 1700335937406035054

In[]:= a+b+c
Out[]= 3759470599491624897

In[]:= a+b+d
Out[]= 5028681613540471324

In[]:= c+d
Out[]= 2131460860763223681

In[]:= b+c
Out[]= 2079657009873287997

In[]:= BaseForm[{a,b,c,d},16]
Out[]//BaseForm= {Subscript[174fe58f4a132484, 16],Subscript[16e0c332c9a0292a, 16],Subscript[5fba9d56685d213, 16],Subscript[1798ce86bbeae46e, 16]}