Modular Equation : Why I'm getting WA?

Hi all,

This is regarding the following question that appeared in last long-challenge : ModularEquation

I read the editorial and I’m not aiming for original constraints at the moment, I want to run my own old code that i couldn’t execute during the contest for sub-task #2,
after reading the editorial, it seems like my approach for sub-task #2 was not wrong however my code is still not getting accepted.

My Code

#define li long long int
using namespace std;
li getMin(li a, li b){
    return (a<=b)?a:b;
int main()
    int t;
        li n,m;
        li ans=0;
        for(li b=2; b <= min(m,n); b++){
            li eq = m - m%b;
            li T = getMin(sqrt(eq)+1, b);
            for(li a=1; a < T; a++){
                if(eq%a == 0){
        // b > m
        for(li b=m+1; b<=n; b++){
            ans += (b-1);
    return 0;

you may also view my submission here
I’m unable to figure out why my code is not even working for testcase #1

whats wrong with the code ? why is it not working for subtask #1 and #2