View Compilation Error

0_0_15599660_12655.cpp:2:2: error: expected unqualified-id before numeric constant
  4 char s[MAXN*2],s1[MAXN],s2[MAXN];
  ^
0_0_15599660_12655.cpp:3:2: error: expected unqualified-id before numeric constant
  5 int main(){
  ^