#include <iostream>#include <cstdio>#include <cstring>using namespace std;const int N=1005;const int zl[8][2]={0, 1, 0, -1, 1, 0, -1, 0, 1, 1, 1, -1, -1, 1, -1, -1};char buff[N][N];bool vs[N][N];int fa[2000005];int cnt[2000005];int n, m;bool in1(int x, int y){return x>=0 && x<=n+1 && y>=0 && y<=m+1;}int find_fa(int x){if(fa[x]!=x) fa[x]=find_fa(fa[x]);return fa[x];}void DFS1(int x, int y){vs[x][y]=1;for(int k=0; k<4; k++){int i=x+zl[k][0];int j=y+zl[k][1];if(in1(i, j) && buff[i][j]!='P' && !vs[i][j]) DFS1(i, j);}}bool in2(int x, int y){return x>=0 && x<=n && y>=0 && y<=m;}void DFS2(int x, int y, int pre){vs[x][y]=1;int f1=find_fa(pre);int f2=find_fa(x*m+y);if(f1!=f2) fa[f1]=f2;for(int k=0; k<8; k++){int i=x+zl[k][0];int j=y+zl[k][1];if(in2(i, j) && buff[i][j]=='P' && !vs[i][j]) DFS2(i, j, x*m+y);}}int main(){while(scanf("%d%d", &n, &m)!=EOF){for(int i=1; i<=n; i++)scanf("%s", buff[i]+1);memset(vs, 0, sizeof vs);DFS1(0, 0);for(int i=1; i<=n; i++)for(int j=1; j<=m; j++){if(buff[i][j]!='P') continue;bool flag=0;for(int k=0; k<4; k++){int x=i+zl[k][0];int y=j+zl[k][1];if(vs[x][y]){flag=1;break;}}if(!flag) buff[i][j]='G';}for(int i=1; i<=n; i++)for(int j=1; j<=m; j++)fa[i*m+j]=i*m+j;memset(vs, 0, sizeof vs);for(int i=1; i<=n; i++)for(int j=1; j<=m; j++){if(buff[i][j]!='P') continue;if(!vs[i][j]) DFS2(i, j, i*m+j);}int ans=0;memset(cnt, 0, sizeof cnt);for(int i=1; i<=n; i++)for(int j=1; j<=m; j++){if(buff[i][j]!='P') continue;cnt[find_fa(i*m+j)]++;}for(int i=1; i<=n; i++){for(int j=1; j<=m; j++)if(ans<cnt[i*m+j]) ans=cnt[i*m+j];}printf("%dn", ans);}return 0;}
