Chico's Floral Print Open Front Tunic-Like Jacket, sz OS

Multi-color, gray background, light reddish flowers Open front; open sleeve; flowing; overblouse; jacket Size tag says "S/M / P/M" but I think it's One Size! I wear M/L and my friend wears a 2X and it fits both of us!! 36 1/2" pit to pit, laid flat