int x = 0;
int y = 400;
int speed = 10;
int gravity = 1;
boolean boolvariable = false;
void setup()
{
background(190,190,190);
size(500,500);
}

void draw()
{
background(190,190,190);
rect (x,y,50,50);

if (speed == - 11) 
{
boolvariable = false;
speed = 10;
}

if (boolvariable)
{
x+=1;
y-=speed;
speed -= gravity;
}

}
void keyPressed()
{
if (key == ' ') 
{
boolvariable = true;

}
}