View Compilation Error

0_0_39686101_17852.cpp: In function 'int main()':
0_0_39686101_17852.cpp:19:13: error: 'ans' was not declared in this scope; did you mean 'abs'?
   19 |             ans = a / 2 * (a+1);
      |             ^~~
      |             abs
0_0_39686101_17852.cpp:22:13: error: 'ans' was not declared in this scope; did you mean 'abs'?
   22 |             ans = (a+1) / 2 * a;
      |             ^~~
      |             abs
0_0_39686101_17852.cpp:24:17: error: 'ans' was not declared in this scope; did you mean 'abs'?
   24 |         cout << ans << "\n";
      |                 ^~~
      |                 abs