func_code_string: #include<bits/stdc++.h>   #define mod 998244353   using namespace std;   int n, A[2], f[200010], pw2;   int powmod(int x, int y){    int ans = 1;    for(;y;y >>= 1, x = 1ll * x * x % mod)     if(y & 1)ans = 1ll * x * ans % mod;    return ans;   }   int main(){    scanf( %d , &n);    A[0] = 1;    A[1] = 0;    pw2 = powmod(2, mod - 2);    for(int i = 1; i <= n; i++){     A[0] = 1ll * A[0] * pw2 % mod;     A[1] = 1ll * A[1] * pw2 % mod;     f[i] = A[!(i & 1)];     A[i & 1] += f[i];    }    printf( %d n , f[n]);   }      