An instructor in chemical warfare asked soldiers in his class: "Anyone knows the formula for water?"
"Sure. That's easy," said one man.
"What is it?"
"H, I, J, K, L, M, N, O."
"What, what?" reasked the instructor.
"H to O," explained the chemistry expert.
If H2O is the formula for water, what is the formula for ice? H2O cubed.