#include <stdio.h>

#define DHT11_PIN 7
#define DHT11_PORT C
#define DHT11_PARSE(port,pin) AS_STRING(P ## port ## pin)
#define DHT11_EVAL(port,pin) DHT11_PARSE(port,pin)
#define DHT11_STRING DHT11_EVAL(DHT11_PORT,DHT11_PIN)
#define AS_STRING( s ) # s

void show(const char* s){
    printf("%s\n", s);
}

int main()
{
    printf("%s\n", DHT11_STRING);
    show(DHT11_STRING);
    return 0;
}