View Compilation Error

0_0_26344102_19725.cpp: In function 'int main()':
0_0_26344102_19725.cpp:40:24: error: expected ')' before ';' token
   for(int i=1<<k;;i<=st;++i) 
                        ^
0_0_26344102_19725.cpp:40:27: error: 'i' was not declared in this scope
   for(int i=1<<k;;i<=st;++i) 
                           ^