If-else statement tackling

I am very confused about if-else statement problem.

The problem is this : using scanf function, assign total(double) and # of absences(int) to s, a, respectively.

Then, print out score based on standards below
if total is above 70, print out A+. In this condition, if absence date is more than 5 days, print out D.

if total is below 70, print out "A0" In this condition, if absence is more than 5 days, print out F.

In coding, you can use only 3 of if-else statement.

#include <stdio.h>

int main(void)
{
    double s;
    int a;
    scanf("%lf%d", &s, &a);
    if (_________________ )
         __________________
         _________________
         _________________
    else
        __________________
        __________________
        ________________
        __________________
        return 0; }

How I approached the problem is this. The total divides into two section, which is divided by the score 70. And then I put another nested if condition to regulate the effect of absence date like if if However, the problem arises out of this. I can't do like if if else if because if can't be included in else statement!!!. I can't use elseif statement neither!! I want to code like

if total >70
    if absence > 5
if total <70
    if absence >5

but the thing is that I can use only if-else 3 statement... Is there any to shorten the code?