#include <fstream>
#include <cstdlib>
#include <time.h>
using namespace std;
int main()
{
	int N,M,B;
	ifstream inp;
	inp.open("subsetselection.in");

	inp>>N>>M>>B;
	int** arr = new int*[N];
	for (int i=0; i<N; i++) {
		arr[i] = new int[M];
		for (int j=0; j<M; j++) {
			inp>>arr[i][j];
		}
	}
	inp.close();
	
	ofstream out;
	out.open("subsetselection.out");
	
	if (N==1) {
		out<<1<<endl;
		out<<1<<endl;
	} else {
		int max = 0;
		int totalRowsMax;
		int* activeRowsMax = new int[N];
		
		int* currentRun = new int[M];
		
		for (int g=0;g<N-1;g++) {
			for (int h=g+1;h<N;h++) {
				int current = 0;
				for (int j=0;j<M;j++) {
					currentRun[j] = arr[g][j]+arr[h][j];
				}
				for (int i=h;i<N;i++) {
					current = 0;
					for (int j=0;j<M;j++) {
						int temp = (currentRun[j]+(h==i?0:arr[i][j]))%B;
						current += temp * temp;
					}
					if (current>max) {
						max = current;
						for (int a=0;a<N;a++) {
							activeRowsMax[a] = 0;
						}
						totalRowsMax = (h==i?2:3);
						activeRowsMax[g] = 1;
						activeRowsMax[h] = 1;
						activeRowsMax[i] = 1; // raboti i za h==i
					}
				}
				if ((float)clock()/CLOCKS_PER_SEC>4.5) {
					break;
				}
			}
			if ((float)clock()/CLOCKS_PER_SEC>4.5) {
				break;
			}
		}
		
		if (N>3) {
			srand(10);
			int* activeRows = new int[N];
			for (int r=0;r<100000;r++) {
				for (int j=0;j<M;j++) {
					currentRun[j] = 0;
				}
				int totalRows = 0;
				for (int i=0;i<N;i++) {
					activeRows[i] = rand()%2;
					if (activeRows[i]) {
						totalRows++;
						int current = 0;
						for (int j=0;j<M;j++) {
							currentRun[j] += arr[i][j];
							current += (currentRun[j]%B) * (currentRun[j]%B);
						}
						if (current>max) {
							max = current;
							totalRowsMax = totalRows;
							for (int a=0;a<N;a++) {
								activeRowsMax[a] = activeRows[a];
							}
						}
					}
					if ((float)clock()/CLOCKS_PER_SEC>4.94) {
						break;
					}
				}
				if ((float)clock()/CLOCKS_PER_SEC>4.94) {
					break;
				}
			}
		}
		
		for (int j=0;j<M;j++) {
			currentRun[j] = 0;
		}
		for (int i=0;i<N;i++) {
			if (activeRowsMax[i]) {
				for (int j=0;j<M;j++) {
					currentRun[j] += arr[i][j];
				}
			}
		}
		for (int i=0;i<N;i++) {
			if (!activeRowsMax[i]) {
				int current = 0;
				for (int j=0;j<M;j++) {
					int temp = (currentRun[j] + arr[i][j])%B;
					current += temp * temp;
				}
				
				if (current>max) {
					max = current;
					totalRowsMax++;
					activeRowsMax[i] = 1;
					for (int j=0;j<M;j++) {
						currentRun[j] += arr[i][j];
					}
					i = 0;
				}
			}
		}

		out<<totalRowsMax<<endl;
		for (int i=0;i<N;i++) {
			if (activeRowsMax[i]) { 
				out<<i+1<<endl;
			}
		}
	}

	out.close();
	
	return 0;
}