View Compilation Error

0_0_1561993_3256.cpp: In function `int main()':
0_0_1561993_3256.cpp:28: error: `res' undeclared (first use this function)
0_0_1561993_3256.cpp:28: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_1561993_3256.cpp:28: error: `cc' cannot be used as a function