View Compilation Error

0_0_26409460_19058.cpp: In function 'int main()':
0_0_26409460_19058.cpp:19:15: error: 'lens' was not declared in this scope
         int i=lens-1,j=lenm-1;
               ^
0_0_26409460_19058.cpp:20:20: error: 'j' was not declared in this scope
         for(;i>=0&&j>=0;i--,j--)
                    ^
0_0_26409460_19058.cpp:47:15: error: 'j' was not declared in this scope
         while(j>=0)
               ^