View Compilation Error

0_0_30241627_28240.cpp:2:1: error: 'usinga' does not name a type
 usinga namespace std;
 ^
0_0_30241627_28240.cpp:4:7: error: redefinition of 'long long int n'
 int n,n,k,T;
       ^
0_0_30241627_28240.cpp:4:5: note: 'long long int n' previously declared here
 int n,n,k,T;
     ^
0_0_30241627_28240.cpp: In function 'int main()':
0_0_30241627_28240.cpp:8:34: error: 'm' was not declared in this scope
         scanf("%lld%lld%lld",&n,&m,&k);
                                  ^