Problems on the Unlocking of "PD7" & "PF0" on TM4C123 using Keil

I am using the TM4C123 and I want to know how  unlock PD0 & PF7 because I would like to use them as GPIOs. 

My Code Is the next: 

#include "TM4C123.h" // Device header

int main()
{

SYSCTL->RCGCGPIO |= (1<<3) ; //Enable clock Port D

GPIOD->LOCK |= 0x4C4F434B;
GPIOD->CR |= 0x0;
GPIOD->DEN |= 0xCF;

GPIOD->DIR |= 0xCF;

GPIOD->DATA |= 0x81; //~(1<<0);


}

A write of the value 0x4C4F.434B unlocks the GPIO Commit (GPIOCR) register for write access. But the line where is the register CR it isnt accepted as a writing register. I would like your help thanks.