This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define in(x) freopen(x, "r", stdin)
#define out(x) freopen(x, "w", stdout)
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-O3")
#define F first
#define S second
#define pb push_back
#define N +100500
#define M ll(1e9 + 7)
#define sz(x) (int)x.size()
#define re return
#define oo ll(1e9)
#define el '\n'
#define pii pair <int, int>
using namespace std;
//using namespace __gnu_pbds;
//typedef tree <int, null_type, less_equal <int> , rb_tree_tag, tree_order_statistics_node_update> ordered_set;
typedef long long ll;
typedef long double ld;
set <pair <int, pair <int, int> > > q;
int mrk[550][550];
char c[550][550];
int go[4][550][550], i, j, n, m, ans, x, y, sx, sy, ex, ey;
void get(int &x, int &y, int &st)
{
    x = (*q.begin()).S.F;
    y = (*q.begin()).S.S;
    st = (*q.begin()).F;
    q.erase(q.begin());
}
void put(int x, int y, int st)
{
    if (mrk[x][y] < st) return;
    q.erase({mrk[x][y], {x, y}});
    q.insert({st, {x, y}});
    mrk[x][y] = st;
}
void Portal(int x, int y, int st)
{
    for (int fst = 0; fst < 4; fst++)
    {
        for (int sd = 0; sd < 4; sd++)
        {
            if (fst == sd) continue;
            int cx = x;
            int cy = y;
            int len = 1;
            if (fst < 2) cy = go[fst][x][y], len += abs(y - cy);
                    else cx = go[fst][x][y], len += abs(x - cx);
            if (sd < 2) cy = go[sd][x][y], cx = x;
                   else cx = go[sd][x][y], cy = y;
//            cerr << fst << " " << sd << " " << x << " " << y << " " << cx << " " << cy << el;
            put(cx, cy, st + len);
        }
    }
}
void putall(int x, int y, int st)
{
    int steps[4][2] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
    for (int i = 0; i < 4; i++)
    {
        int cx = x + steps[i][0];
        int cy = y + steps[i][1];
        if (cx < 1 || cy < 1 || cx > n || cy > m || c[cx][cy] == '#') continue;
        put(cx, cy, st + 1);
    }
    Portal(x, y, st);
}
int main()
{
    srand(time(0));
    ios_base::sync_with_stdio(0);
    iostream::sync_with_stdio(0);
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
//    in("input.txt");
//    out("output.txt");
    cin >> n >> m;
    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= m; j++)
        {
            cin >> c[i][j];
            if (c[i][j] == 'C') sx = i, sy = j;
            if (c[i][j] == 'F') ex = i, ey = j;
            mrk[i][j] = 1e9;
        }
    }
    int lst;
    for (i = 1; i <= n; i++)
    {
        for (j = 1; j <= m; j++)
        {
            if (c[i][j] == '#') lst = j;
            go[0][i][j] = lst + 1;
        }
        for (j = m; j >= 1; j--)
        {
            if (c[i][j] == '#') lst = j;
            go[1][i][j] = lst - 1;
        }
    }
    for (j = 1; j <= m; j++)
    {
        for (i = 1; i <= n; i++)
        {
            if (c[i][j] == '#') lst = i;
            go[2][i][j] = lst + 1;
        }
        for (i = n; i >= 1; i--)
        {
            if (c[i][j] == '#') lst = i;
            go[3][i][j] = lst - 1;
        }
    }
    put(sx, sy, 0);
    while (sz(q))
    {
        int st;
        get(x, y, st);
        putall(x, y, st);
    }
    if (mrk[ex][ey] == oo) cout << "nemoguce";
                      else cout << mrk[ex][ey] << el;
 }
//
//110000
//1100
Compilation message (stderr)
portal.cpp: In function 'int main()':
portal.cpp:139:31: warning: 'lst' may be used uninitialized in this function [-Wmaybe-uninitialized]
             go[2][i][j] = lst + 1;
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