View Compilation Error

0_0_16007520_7168.cpp: In function 'int main()':
0_0_16007520_7168.cpp:16:16: error: 'xx' was not declared in this scope
       square=0;xx=yy=1;
                ^
0_0_16007520_7168.cpp:16:19: error: 'yy' was not declared in this scope
       square=0;xx=yy=1;
                   ^