Codeforces Round #667 (Div. 3) problem C

```
#include <bits/stdc++.h>
using namespace std;
int main() {
int tcs;
cin >> tcs;
while (tcs--) {
int n, x, y;
cin >> n >> x >> y;
int diff = y - x;
for (int delta = 1; delta <= diff; ++delta) {
if (diff % delta) continue;
if (diff / delta + 1 > n) continue;
int k = min((y - 1) / delta, n - 1);
int a0 = y - k * delta;
for (int i = 0; i < n; ++i) {
cout << (a0 + i * delta) << ' ';
}
cout << endl;
break;
}
}
}
```

can any one explain what is concept behind a0 (the first term)

your effort is really appreciated and thanks for help