View Compilation Error

0_0_1655723_1191.cpp:1: error: `ACMAlgorithm' has not been declared
0_0_1655723_1191.cpp:1: error: expected namespace-name before ';' token
0_0_1655723_1191.cpp:1: error: `<type error>' is not a namespace
0_0_1655723_1191.cpp: In function `int main()':
0_0_1655723_1191.cpp:8: error: `CBigInt' undeclared (first use this function)
0_0_1655723_1191.cpp:8: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_1655723_1191.cpp:8: error: expected `;' before "r"
0_0_1655723_1191.cpp:9: error: `cin' undeclared (first use this function)
0_0_1655723_1191.cpp:11: error: `r' undeclared (first use this function)
0_0_1655723_1191.cpp:17: error: `cout' undeclared (first use this function)
0_0_1655723_1191.cpp:17: error: `endl' undeclared (first use this function)