View Compilation Error

0_0_36264054_29175.cpp: In function 'void dfs(ll, ll, ll, int)':
0_0_36264054_29175.cpp:27:6: error: '__int64_t' was not declared in this scope
  if((__int64_t)mul*calc(sqrt(y/x))<=ans)return;
      ^
0_0_36264054_29175.cpp:27:16: error: expected ')' before 'mul'
  if((__int64_t)mul*calc(sqrt(y/x))<=ans)return;
                ^