title: what is the result of modulo opeartion on (a-b)%n
body: <p>Recently i solved a problem where i have to compute (a-b)%n.The results were self explanatory when a-b is an positive number but for negative numbers the results that i got seems confusing..i just wanted to know how can we calculate this result for negative numbers.</p>
  
  <p>Any links dealing with modulo operator properties are most welcome.</p>