I got AC.
My solution uses simple stack with 15 elements in each node. System memory management functions have some memory overhead, so I take mem from static 512k heap. Memory freeing wasn't realized. When some POPs make node empty memory leaks. And next PUSH will alloc new node. Many POP-PUSH crash my programm.

Here is example of such test
#include <stdio.h>
int main()
{
printf ("40015\n");
int i;
for (i=0;i<15;++i)
printf ("PUSH 1 %d\n", i+1);  // full 1 node
for (i=0;i<10000;++i)
printf ("PUSH 1 %d\nPOP 1\nPOP 1\nPUSH 1 %d\n", i+1,i+100000);
return 0;
}