The term SOLVER'S SHOUT is a phrase used to describe the exclamation of joy and triumph when someone solves a difficult problem. It is often expressed as either 'AHA!' or 'EUREKA!', both of which are 3 and 6 letters respectively. AHA is an expression of surprise or realization, while EUREKA is an expression of joy and triumph. Both terms are used to express the same sentiment, but EUREKA is more commonly used in modern times.