#include<cstring>#include<cstdio>#include<algorithm>#include<string>using namespace std;char s[110];string t[60];int n,m;int dp[110];int main(){ while(scanf("%d %d",&n,&m)!=EOF){ getchar(); int ans=0; for(int i=0;i<n;i++){ for(int j=0;j<m;j++){ gets(s); t[j]=s; } memset(dp,0,sizeof(dp)); dp[0]=1; int now=1; for(int j=1;j<m;j++){ dp[j]=1; for(int k=0;k<j;k++) if(t[k]<=t[j]) dp[j]=max(dp[j],dp[k]+1); now = max(now,dp[j]); } ans+=(m-now); } printf("%dn",ans); } return 0;}
