View Compilation Error

0_0_28939755_29509.cpp:8:1: error: expected initializer before 'long'
 long long n,m;
 ^
0_0_28939755_29509.cpp: In function 'int main()':
0_0_28939755_29509.cpp:21:8: error: 'n' was not declared in this scope
   cin>>n>>m;
        ^
0_0_28939755_29509.cpp:21:11: error: 'm' was not declared in this scope
   cin>>n>>m;
           ^
0_0_28939755_29509.cpp:24:10: error: 'b' was not declared in this scope
   memset(b,0,sizeof(b));
          ^