View Compilation Error

0_0_2471216_13336.cpp: In function `int main()':
0_0_2471216_13336.cpp:13: error: `abs' undeclared (first use this function)
0_0_2471216_13336.cpp:13: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2471216_13336.cpp:15: error: `b' is not a type
0_0_2471216_13336.cpp:15: error: request for member of non-aggregate type before ',' token