The expression
\[a^3 (b^2 - c^2) + b^3 (c^2 - a^2) + c^3 (a^2 - b^2)\]can be factored into the form  $(a - b)(b - c)(c - a) p(a,b,c),$ for some polynomial $p(a,b,c).$  Find $p(a,b,c).$
<|im_start|>system
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<|im_start|>user
The expression
\[a^3 (b^2 - c^2) + b^3 (c^2 - a^2) + c^3 (a^2 - b^2)\]can be factored into the form  $(a - b)(b - c)(c - a) p(a,b,c),$ for some polynomial $p(a,b,c).$  Find $p(a,b,c).$
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-(ab + ac + bc)
The expression
\[a^3 (b^2 - c^2) + b^3 (c^2 - a^2) + c^3 (a^2 - b^2)\]can be factored into the form  $(a - b)(b - c)(c - a) p(a,b,c),$ for some polynomial $p(a,b,c).$  Find $p(a,b,c).$
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