main.c_ver3_WORKING

#include <stm32f10x.h>
#include <stm32f10x_rcc.h>
#include <stm32f10x_gpio.h>
//include H
void delay(volatile uint32_t nCount) {
    for (; nCount != 0; nCount--);
}
//timer_to_future_use
int i;
//i
volatile void main(void)
{
  RCC->APB2ENR|=RCC_APB2ENR_IOPCEN; //power up PORT_C
  GPIOC->CRH=0x80200000; //PORT_C_15 = input, push_down ,, PORT_C_13 = output
   for(i=1;i!=0;i++){ //starting cycle
  if(GPIOC->IDR&GPIO_IDR_IDR15)GPIOC->BRR=(1<<13); //if button presed - push down PORT_C_13
  else
    GPIOC->BSRR=(1<<13); //IF not pressed - push up PORT_C_13 (led)
  }
}