View Compilation Error

0_0_38066786_4473.cpp: In function 'int solve(int)':
0_0_38066786_4473.cpp:67:25: error: 'v' was not declared in this scope
     for(int _=0;_<40 && v<u;_++,v*=2.0)
                         ^
0_0_38066786_4473.cpp:67:27: error: 'u' was not declared in this scope
     for(int _=0;_<40 && v<u;_++,v*=2.0)
                           ^