Precedency of Postfix and prefix operator in C

Question

I am finding difficulty to understand how precedency works in the following case. Can anyone explain why the answer is different in below two printf functions?

int main()
{

    int a=10,b=20,c;
    c= a++ + ++a - --b - b-- + ++a;
    printf("%d\n",c);
    printf("%d",a++ + ++a - --b - b-- + ++a);
    return 0;
}