Pointer to an integer

MY_PROG: PROC OPTIONS(MAIN);
    DCL CENTRY EXTERNAL ENTRY;
    DCL I FIXED BIN(31);
    DCL P POINTER;
    P = ADDR(I);
    I = 5;
    CALL CENTRY (P);
END MY_PROG;
 

#pragma linkage (centry,PLI)
#include <stdio.h>
void centry(int **x)
{
  printf("Value is %d\n",**x);
}