#include<cstdlib>#include<cstdio>#include<cstring>#include<cmath>#include<queue>#include<algorithm>#include<iostream>using namespace std;int equ,var;int x[55];int a[55][55];int nofree_num;void debug(){ for(int i=0; i<equ; i++) { for(int j=0; j<=var; j++) printf("%d ",a[i][j]); puts(""); } puts("");}int gcd(int x,int y){ return y?gcd(y,x%y):x;}int lcm(int x,int y){ return x/gcd(x,y)*y;}int dfs(int p,int q) // 从矩阵下方向上枚举每个x[i]∈{0,1,2} 看等式是否成立，当成立时跳上上一行继续枚举， 如果当前行无解则返回0{ int i,j; if(p==-1) return 1; for(i=0; i<3; i++) { int tep=a[p][var]; for(j=p+1; j<var; j++) tep=(tep%q-(x[j]*a[p][j])%q+q)%q; if((i*a[p][p])%q==tep) { x[p]=i; return dfs(p-1,q); } } return 0;}int gauss(int p){ int i,j,k; int row,col; for(row=0,col=0; row<equ&&col<var; row++,col++) { int maxr=row; for(i=row+1; i<equ; i++) if(abs(a[i][col])>abs(a[maxr][col])) maxr=i; if(a[maxr][col]==0) { row--; continue; } for(i=0; i<=var; i++) swap(a[row][i],a[maxr][i]); for(i=row+1; i<equ; i++) { if(a[i][col]) { int LCM=lcm(abs(a[row][col]),abs(a[i][col])); int ta=LCM/abs(a[row][col]); int tb=LCM/abs(a[i][col]); if(a[i][col]*a[row][col]<0) ta=-ta; for(j=col; j<=var; j++) a[i][j]=((a[i][j]*tb)%p-(a[row][j]*ta)%p+p)%p; } } } for(i=row; i<equ; i++) if(a[i][var]) return 0; for(i=0; i<equ; i++) { if(a[i][i]==0) { for(j=i+1; j<var; j++) if(a[i][j]) break; if(j==var) break; for(k=0; k<equ; k++) swap(a[k][i],a[k][j]); } } nofree_num=row; return dfs(var-1,p);}int main(){ int t; cin>>t; while(t--) { int q,n; int A[55]; int i,k; cin>>q>>n; equ=var=n; for(i=0; i<n; i++) cin>>A[i]; memset(a,0,sizeof(a)); for(k=0; k<n; k++) { for(i=0; i<=k; i++) a[k][k-i]=A[i]; for(i=k+1; i<=n-1; i++) a[k][n+k-i]=A[i]; } a[0][var]=1; puts(gauss(q)?"A solution can be found":"No solution"); }}
