View Compilation Error

0_0_14132349_10935.cpp: In function 'int main()':
0_0_14132349_10935.cpp:31:13: error: 'ans' was not declared in this scope
             ans --;
             ^
0_0_14132349_10935.cpp:37:13: error: 'ans' was not declared in this scope
             ans = max (ans, max(y1, y2));
             ^
0_0_14132349_10935.cpp:39:25: error: 'ans' was not declared in this scope
         printf ("%d\n", ans);
                         ^