关于今晚ABC D，调了一小时

#include<bits/stdc++.h>
#define int long long
#define double long double
#define INF INT_MAX
using namespace std;
int n,m,k,ans=INF;
vector<vector<char> > a;
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	cin>>n>>m>>k;
	a.resize(n+10);
	for(int i=1;i<=n;i++){
		a[i].resize(m+10);
		for(int j=1;j<=m;j++){
			cin>>a[i][j];
		}
	}
	for(int i=1;i<=n;i++){
		int l=1,zans=INF,osum=0,dsum=0;
		for(int j=1;j<=m;j++){
			if(a[i][j]=='x'){
				l=j+1;	
				osum=dsum=0;
				continue;
			}
			if(a[i][j]=='o') osum++;
			if(a[i][j]=='.') dsum++;
			if(osum+dsum>k){
				if(l>m) break;
				if(a[i][l]=='.')  dsum--;
				if(a[i][l]=='o') osum--;
				l++;
			}
			if(osum+dsum==k) zans=min(zans,dsum);
		}
		ans=min(ans,zans);
	}
	for(int i=1;i<=m;i++){
		int l=1,zans=INF,osum=0,dsum=0;
		for(int j=1;j<=n;j++){
			if(a[j][i]=='x'){
				l=i+1;	
				osum=dsum=0;
				continue;
			}
			if(a[j][i]=='o') osum++;
			if(a[j][i]=='.') dsum++;
			if(osum+dsum>k){
				if(l>n) break;
				if(a[l][i]=='.') dsum--;
				if(a[l][i]=='o') osum--;
				l++;
			}
			if(osum+dsum==k) zans=min(zans,dsum);
		}
		ans=min(ans,zans);
	}
	if(ans!=INF) cout<<ans<<endl;
	else cout<<-1<<endl;
	return 0;
}