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var pantalla = document.querySelector("canvas");
var pincel = pantalla.getContext("2d");
pincel.fillStyle = "darkgreen";
pincel.fillRect(0,0,350,300);
pincel.fillStyle = "black";
pincel.fillRect(47,40,90,90);
pincel.fillStyle = "black";
pincel.fillRect(205,40,90,90);
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pincel.fillRect(135,130,70,100);
pincel.fillStyle = "black";
pincel.fillRect(100,200,40,100);
pincel.fillStyle = "black";
pincel.fillRect(200,200,40,100);
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