View Compilation Error

0_0_15320897_26705.cpp: In function 'int main()':
0_0_15320897_26705.cpp:6:5: error: expected initializer before 'op'
     op=getchar()
     ^
0_0_15320897_26705.cpp:9:22: error: 'op' was not declared in this scope
     while(scanf("%c",op)) 
                      ^