Generating image sizes

How can I prevent the plugin from generating so many image sizes? I’m just using the plugin in this pages
http://www.costabravaparcaventura.com/fotos-2/
http://www.costabravaparcaventura.com/circuit-illes-formigues/ and
http://www.costabravaparcaventura.com/dt_galleries/per-empreses/
We I upload an image it generates 19 different sizes.

Thank you!

https://ww.wp.xz.cn/plugins/wc-gallery/