View Compilation Error

0_0_1948235_20866.cpp: In function `int main()':
0_0_1948235_20866.cpp:6: error: expected init-declarator before "cin"
0_0_1948235_20866.cpp:6: error: expected `,' or `;' before "cin"
0_0_1948235_20866.cpp:7: error: `B' undeclared (first use this function)
0_0_1948235_20866.cpp:7: error: (Each undeclared identifier is reported only once for each function it appears in.)