#include <iostream>
using namespace std;
int main() {
const int MAX_SIZE = 20;
int n, m, mt[MAX_SIZE + 1][MAX_SIZE + 1];
cin >> n >> m;
for (int i = 1; i <= n; ++i) {
for (int j = 1; j <= m; ++j) {
cin >> mt[i][j];
}
}
int tweens = 0;
for (int j = 2; j <= m; ++j) {
int counter = 0;
for (int i = 1; i <= n; ++i) {
if (mt[i][j] > mt[i][j - 1]) {
++counter;
}
}
if (counter == n) {
++tweens;
}
}
cout << tweens;
return 0;
}
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