View Compilation Error

0_0_6824905_12472.cpp:2: error: expected nested-name-specifier before "namespacestd"
0_0_6824905_12472.cpp:2: error: `namespacestd' has not been declared
0_0_6824905_12472.cpp:4: error: ISO C++ forbids declaration of `intmain' with no type
0_0_6824905_12472.cpp: In function `int intmain()':
0_0_6824905_12472.cpp:5: error: `doublea' undeclared (first use this function)
0_0_6824905_12472.cpp:5: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_6824905_12472.cpp:5: error: `b' undeclared (first use this function)
0_0_6824905_12472.cpp:6: error: `cin' undeclared (first use this function)
0_0_6824905_12472.cpp:6: error: `a' undeclared (first use this function)
0_0_6824905_12472.cpp:7: error: `cout' undeclared (first use this function)
0_0_6824905_12472.cpp:7: error: `endl' undeclared (first use this function)
0_0_6824905_12472.cpp:8: error: `return0' undeclared (first use this function)