game wont launch

Minecraft Crash Report ----
// Oh - I know what I did wrong!

Time: 6/19/16 6:17 PM
Description: Initializing game

java.lang.OutOfMemoryError: Java heap space
at java.awt.image.DataBufferByte.<init>(DataBufferByte.java:92)
at java.awt.image.ComponentSampleModel.createDataBuffer(ComponentSampleModel.java:445)
at java.awt.image.Raster.createWritableRaster(Raster.java:941)
at javax.imageio.ImageTypeSpecifier.createBufferedImage(ImageTypeSpecifier.java:1074)
at javax.imageio.ImageReader.getDestination(ImageReader.java:2892)
at com.sun.imageio.plugins.png.PNGImageReader.readImage(PNGImageReader.java:1309)
at com.sun.imageio.plugins.png.PNGImageReader.read(PNGImageReader.java:1606)
at javax.imageio.ImageIO.read(ImageIO.java:1448)
at javax.imageio.ImageIO.read(ImageIO.java:1352)
at bwh.a(SourceFile:377)
at bwe.a(SourceFile:219)
at bwd.a(SourceFile:190)
at bwd.b(SourceFile:149)
at bwd.a(SourceFile:76)
at byo.m(SourceFile:727)
at byo.a(SourceFile:172)
at byp.a(SourceFile:23)
at bxi.a(SourceFile:100)
at bcx.an(SourceFile:517)
at bcx.a(SourceFile:381)
at net.minecraft.client.main.Main.main(SourceFile:124)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Thread: Client thread
Stacktrace:
at java.awt.image.DataBufferByte.<init>(DataBufferByte.java:92)
at java.awt.image.ComponentSampleModel.createDataBuffer(ComponentSampleModel.java:445)
at java.awt.image.Raster.createWritableRaster(Raster.java:941)
at javax.imageio.ImageTypeSpecifier.createBufferedImage(ImageTypeSpecifier.java:1074)
at javax.imageio.ImageReader.getDestination(ImageReader.java:2892)
at com.sun.imageio.plugins.png.PNGImageReader.readImage(PNGImageReader.java:1309)
at com.sun.imageio.plugins.png.PNGImageReader.read(PNGImageReader.java:1606)
at javax.imageio.ImageIO.read(ImageIO.java:1448)
at javax.imageio.ImageIO.read(ImageIO.java:1352)
at bwh.a(SourceFile:377)
at bwe.a(SourceFile:219)
at bwd.a(SourceFile:190)
at bwd.b(SourceFile:149)
at bwd.a(SourceFile:76)
at byo.m(SourceFile:727)
at byo.a(SourceFile:172)
at byp.a(SourceFile:23)
at bxi.a(SourceFile:100)
at bcx.an(SourceFile:517)

– Initialization –
Details:
Stacktrace:
at bcx.a(SourceFile:381)
at net.minecraft.client.main.Main.main(SourceFile:124)