Constanze's Machine CF

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define mod (int)(1e9+7)
#define MAXI (int)(1e15+100)
#define N 100005

int power(int a,int m1)
{
    if(m1==0)return 1;
    else if(m1==1)return a;
    else if(m1==2)return (1LL*a*a)%mod;
    else if(m1&1)return (1LL*a*power(power(a,m1/2),2))%mod;
    else return power(power(a,m1/2),2)%mod;
}


// Driver code to tes above functions
int32_t main()
{


    #ifndef ONLINE_JUDGE
    // for getting input from inpu.txt
    freopen("input.txt", "r", stdin);
    // for writing output to output.txt
    //freopen("output.txt", "w", sdtout);
    #endif

    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);

    string s;
    cin >> s;

    int pre[N];
    pre[0] = 0;
    pre[1] = 1;
    for(int i=2;i<N;i++)
    {
        if(i%3==0)
            pre[i] = ((2*pre[i-1])%mod - pre[i-2] + mod)%mod;
        else if(i%3==1)
            pre[i] = (pre[i-1] + pre[i-2])%mod;
        else
            pre[i] = ((2*pre[i-1])%mod + pre[i-2])%mod;
    }

    int n = s.size(), w=0,m=0;
    for(int i=0;i<n;i++)
    {
        if(s[i]=='w')
            w++;
        if(s[i]=='m')
            m++;
    }

    int ans = 1;
    if(w!=0 or m!=0)
    {
        cout << 0;
        return 0;
    }
    else
    {
        for(int i=0;i<n;i++)
        {
            if(s[i]=='n' or s[i]=='u')
            {
                int c = 0, j;
                for(j=i;j<n and s[j]==s[i];j++)
                    c++;
                int k = pre[c];
                ans= (ans * k)%mod;
                i = j-1;
            }

        }
    }

    cout << ans;

    return 0;

}