View Compilation Error

0_0_6219737_693.cpp: In function `int main()':
0_0_6219737_693.cpp:20: error: `ans' undeclared (first use this function)
0_0_6219737_693.cpp:20: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6219737_693.cpp:20: error: `x' undeclared (first use this function)