#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(void){
    int i,count=1;
    int origin[100],rule[100],before[100],after[100];
    for(i=0;i<100;i++){
        origin[i]=i;
        rule[i]=i;
        before[i]=i;
    }
    int n,k,x,y,tmp;
    scanf("%d%d",&n,&k);
    for(i=0;i<k;i++){
        scanf("%d%d",&x,&y);
        tmp=rule[y-1];
        rule[y-1]=rule[x-1];
        rule[x-1]=tmp;
    }
    while(1){
        for(i=0;i<n;i++){
            after[i]=before[rule[i]];
        }
        if(memcmp(after,origin,4*n)==0){
            printf("%d\n",count);
            return 0;
        }
        memcpy(before,after,4*n);
        count++;
    }
}