#include using namespace std; typedef signed long long ll; #undef _P #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) //------------------------------------------------------- const int MAT=64; struct Mat { double v[MAT][MAT]; Mat(){ZERO(v);};}; Mat mulmat(Mat& a,Mat& b,int n=MAT) { int x,y,z; Mat r; FOR(x,n) FOR(z,n) FOR(y,n) r.v[x][y] += a.v[x][z]*b.v[z][y]; return r; } Mat powmat(ll p,Mat a,int n=MAT) { int i,x,y; Mat r; FOR(x,n) FOR(y,n) r.v[x][y]=0; FOR(i,n) r.v[i][i]=1; while(p) { if(p%2) r=mulmat(r,a,n); a=mulmat(a,a,n); p>>=1; } return r; } int H,W,T; int SY,SX,GY,GX; string S[10]; Mat P,Q; void solve() { int i,j,k,l,r,x,y; string s; cin>>H>>W>>T; cin>>SY>>SX>>GY>>GX; SY--,SX--,GY--,GX--; FOR(y,10) { if(y>S[y]; S[y]=S[y]+"############"; S[y]=S[y].substr(0,10); } for(y=1;y<=8;y++) { for(x=1;x<=8;x++) if(S[y][x]=='.') { if(y==GY+1 && x==GX+1) continue; int d[4]={1,0,-1,0}; int cnt=0; FOR(i,4) { int ty=y+d[i]; int tx=x+d[i^1]; if(S[ty][tx]=='.') cnt++; } if(cnt) { FOR(i,4) { int ty=y+d[i]; int tx=x+d[i^1]; if(S[ty][tx]=='.') P.v[(ty-1)*8+(tx-1)][(y-1)*8+(x-1)]=1.0/cnt; } } } } Q=powmat(T,P); double ret=Q.v[GY*8+GX][SY*8+SX]; _P("%.12lf\n",ret); } int main(int argc,char** argv){ string s;int i; if(argc==1) ios::sync_with_stdio(false), cin.tie(0); FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin); cout.tie(0); solve(); return 0; }