Scrolling Sign

#include<bits/stdc++.h>

using namespace std;

int prefix[103],len;

string s,text,pattern;

void compute_prefix()
{
    int i,j=0;

    prefix[1] = 0;

    for(i=2; i<=len; i++)
    {
        while(j && pattern[j+1]!=pattern[i])
        {
            j = prefix[j];
        }

        if(pattern[j+1]==pattern[i])
        {
            j++;
        }

        prefix[i] = j;
    }
}

int KMP_match()
{
    int i,j=0;

    int mx = 0;

    for(i=1; i<=len; i++)
    {
        while(j && pattern[j+1]!=text[i])
        {
            j = prefix[j];
        }

        if(pattern[j+1]==text[i])
        {
            j++;
        }

    }

    return j;
}



int main()
{
    int n,test,i,j,k,w,ans;

    scanf("%d",&test);

    while(test--)
    {
        scanf("%d%d",&k,&w);

        len = k;

        cin>>s;

        text = " "+s;

        ans = 0;

        for(i=2;i<=w;i++)
        {
            cin>>s;

            pattern = " "+s;

            compute_prefix();

            n = KMP_match();

            ans+=len-n;

            text = pattern;
        }

        printf("%d\n",ans+len);
    }

    return 0;
}