I'm looking to buy sweat-wide pants, but I'm having trouble deciding between a small and medium size. I'm 5'9 (175 cm) tall, weigh 55 kg (121 lbs), and have a slim build. My waistline is probably around 29-30 inches, but I'm not entirely sure. I'd like the pants to be a bit shorter so they don't reach the floor. Can anyone help me figure out which size would be the best fit?