View Compilation Error

0_0_15252285_8455.cpp: In function 'int main()':
0_0_15252285_8455.cpp:61:9: error: 'else' without a previous 'if'
         else cas=1;
         ^
0_0_15252285_8455.cpp:61:14: error: 'cas' was not declared in this scope
         else cas=1;
              ^