View Compilation Error

0_0_36511348_1763.cpp: In function 'int main()':
0_0_36511348_1763.cpp:46:19: error: 'h' was not declared in this scope
             ans = h * inv(2 * r1, mod) % mod;
                   ^
0_0_36511348_1763.cpp:48:40: error: 'h' was not declared in this scope
             ans = (mod + 1 - (2 * r1 - h) * inv(2 * r1, mod)) % mod;
                                        ^