Virus DFS

#include <stdio.h>
#define MAX 101

int count = 0;
int visits[MAX];
int metrix[MAX][MAX];

void DFS (int v, int N) {
    visits[v] = 1;
    
    for (int i = 1; i <= N; i++) {
        if (!visits[i] && metrix[v][i]) {
            count++;
            DFS(i, N);
        }
    }
}

int main(void) {
    int N = 0;
    int E = 0;
    
    scanf("%d", &N);
    scanf("%d", &E);
    
    for (int i = 0; i < E; i++) {
        int firstV, secondV;
        scanf("%d %d", &firstV, &secondV);
        
        metrix[firstV][secondV] = 1;
        metrix[secondV][firstV] = 1;
    }
    
    DFS(1, N);
    
    printf("%d\n", count);
    
    return 0;
}