View Compilation Error

0_0_34194591_18930.cpp: In function 'int main()':
0_0_34194591_18930.cpp:16:31: error: 'fabs' was not declared in this scope
   int ans = (int)(fabs(t1 - t2)>180 ? 360 - fabs(t1 - t2) : fabs(t1 - t2));
                               ^