View Compilation Error

0_0_36513953_5841.cpp: In function 'void solve()':
0_0_36513953_5841.cpp:39:54: error: 'R' was not declared in this scope
     if(4ll*g*t*t*t*v+4ll*v*v*t*t+1ll*g*g*t*t*t*t-4ll*R*R>=8ll*g*t*t*t*v) {
                                                      ^