View Compilation Error

0_0_37723075_23015.cpp:7:7: error: 'MAXN' was not declared in this scope
 int f[MAXN];
       ^
0_0_37723075_23015.cpp: In function 'int main()':
0_0_37723075_23015.cpp:12:9: error: 'f' was not declared in this scope
  memset(f, 0x3f, sizeof f);
         ^
0_0_37723075_23015.cpp:24:3: error: 'll' was not declared in this scope
   ll x, res=0;
   ^
0_0_37723075_23015.cpp:25:18: error: 'x' was not declared in this scope
   scanf("%lld", &x);
                  ^
0_0_37723075_23015.cpp:26:3: error: 'res' was not declared in this scope
   res+=x/79205*7*31;
   ^
0_0_37723075_23015.cpp:28:23: error: 'INF' was not declared in this scope
   if (res==0 && f[x]==INF)
                       ^