View Compilation Error

0_0_37660340_22998.cpp: In function 'bign mult(bign, bign)':
0_0_37660340_22998.cpp:28:17: error: expected unqualified-id before '[' token
   c.num[i+1]+=c.[num]/10;
                 ^
0_0_37660340_22998.cpp:28:18: error: 'num' was not declared in this scope
   c.num[i+1]+=c.[num]/10;
                  ^
0_0_37660340_22998.cpp:29:5: error: expected unqualified-id before '[' token
   c.[num]%=10;
     ^