#include <bits/stdc++.h>
using namespace std;
#define print(l) for(auto i:l) cout<<i<<" ";cout<<endl;
#define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i];
#define int long long
#define pb push_back
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> 
#define all(l) l.begin(),l.end()
#define pii pair<int,int>
#define fi first
#define se second
const int M = 1e9+7;
const int inf = 1e18;
int bp(int x, int y, int p){
    int res = 1;
    x = x % p;
    while (y > 0) {
 
        if (y & 1)
            res = (res * x) % p;
        y = y >> 1;
        x = (x * x) % p;
    }
    return res;
}
 
int MI(int n, int p){
    return bp(n, p - 2, p);
}
int mul(int x,int y, int p){
    return x * 1ull * y % p;
}
int di(int x,int y, int p){
    return mul(x, MI(y, p), p);
}
int n , m , k , q;
void solve(int testcase_number){
    cin>>n>>q;
    string a,b;
    cin>>a>>b;
		string oa = a; 
		string ob = b;
    q++;
	while(q--){
	    for(int i =0 ;i<n;i++){
	    	if(i+1<n and a[i]-'a' < b[i]-'a'){
	    		a[i+1] = (char)a[i+1]+abs(a[i]-b[i]);
	    		a[i] = b[i];
	    	}
	    	else if(i+1<n){
	    		b[i+1] = (char)b[i+1]+abs(b[i]-a[i]);
	    		b[i] = a[i];
	    	}
	    }
	    if(a == b){
	    	cout<<"da"<<endl;
	    }
	    else{
	    	cout<<"ne"<<endl;
	    }
	    int i;
	    char k;
	    a = oa;
	    b = ob;
	    if(q >= 1)
	    cin>>i>>k;
	    a[i-1] = k;
	    oa = a;
	}
    // cout<<a<<endl;
    // cout<<b<<endl;
    // cout<<endl;
    
}
signed main(){
    ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
    cin.tie(0), cout.tie(0);
    cout << fixed<<setprecision(9);
    int t = 1;
    // cin>>t;
    for(int i = 1;i<=t;i++){
        solve(i);
    }
}
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... | 
| # | Verdict | Execution time | Memory | Grader output | 
|---|
| Fetching results... |