how does the increment operator work when an expression is printed inside and when it is assigned to a variable and then it is printed

Question

Program 1

#include <stdio.h>

int main()
{
   int a = 10, m;

   m = a++ + ++a - a++;

   printf("%d %d", m, a);
}

Program 2

#include <stdio.h>

int main()
{
   int a = 10;

   printf("value of m=%d", a++ + ++a - a++);
}