View Compilation Error

0_0_2548851_3797.cpp: In function `int main()':
0_0_2548851_3797.cpp:14: error: `abs' undeclared (first use this function)
0_0_2548851_3797.cpp:14: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_2548851_3797.cpp: At global scope:
0_0_2548851_3797.cpp:29: error: stray '\26' in program