View Compilation Error

0_0_37678525_25216.cpp: In function 'int gintcd(int, int)':
0_0_37678525_25216.cpp:122:20: error: 'gcd' was not declared in this scope
   return gcd(b, a%b);
                    ^
0_0_37678525_25216.cpp: In function 'void updateSecond(int, int, int, int, int, int)':
0_0_37678525_25216.cpp:136:32: error: 'gcd' was not declared in this scope
    f[root] = gcd(lazy[root],val);
                                ^