class Math{
function int multiply(int x, int y){}
function int divide(int x, int y){}
function int min(int x, int y){}
function int max(int x, int y){}
function int sqrt(int x){}
}
class String{
constructor String new(int maxLength){}
method int dispose(){}
method int length(){}
method char charAt(int j){}
method void setCharAt(int j, char c){}
method String appendChar(char c){}
method void eraseLastChar(){}
method int intValue(){}
method void setInt(int val){}
function char backSpace(){}
function char doubleQuote(){}
function char newLine(){}
}
class Array{
function Array new(int size){}
method void dispose(){}
}
class Output{
function void moveCursor(int i, int j){}
function void printChar(char c){}
function void printString(String s){}
function void printInt(int i){}
function void println(){}
function void backSpace(){}
}
class Screen{
function void clearScreen(){}
function void setColor(boolean b){}
function void drawPixel(int x, int y){}
function void drawLine(int x1, int y1, int x2, int y2){}
function void drawRectangle(int x1, int y1, int x2, int y2){}
function void drawCircle(int x, int y, int r){}
}
class Keyboard{
function char keyPressed(){}
function char readChar(){}
function String readLine(String message){}
function int readInt(String message){}
}
class Memory{
function int peek(int address){}
function void poke(int address, int value){}
function Array alloc(int size){}
function void deAlloc(Array o){}
}
class Sys{
function void halt(){}
function void error(int errorCode){}
function void wait(int duration){}
}