View Compilation Error

0_0_32001822_15646.cpp: In function 'int main()':
0_0_32001822_15646.cpp:4:5: error: declaration does not declare anything [-fpermissive]
     char;
     ^
0_0_32001822_15646.cpp:6:25: error: 'ch' was not declared in this scope
     while(scanf("%c%d",&ch,&n)&&ch!='@')
                         ^
0_0_32001822_15646.cpp:15:32: error: expected ';' before ')' token
             for(k=0;k<2*i-3;k++)
                                ^