Help me in solving VACCINE2 problem

help
,
1

My issue

while using ternary operator instead of (if/else) it is giving WA : wrong answer while submitting it and if i’m using if-else it is giving correct o/p what could be the reason ?

My code

#include<bits/stdc++.h>
using namespace std;
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int t; cin >> t;
    while(t--) {
        int people , days;
        cin >> people >> days;
        int risk = 0 , safe = 0 , ans1 = 0;
        while(people--) {
            int x; cin >> x;
            if (x >= 80 || x <= 9) risk++;
            else safe++;
        }
        ans = (risk&1) ? (risk/days)+1 : risk/days;
        ans += (safe&1) ? (safe/days)+1 : safe/days;
        
        cout << ans << '\n';
    }
}

Problem Link: VACCINE2 Problem - CodeChef