Sergeant EXAM07

#include<stdio.h>

int abs(int a){
    return (a < 0 ? a*-1 : a);
}
int min(int a,int b){
    return (a < b ? a : b);
}
int arr[55];
int main(){
    int a,b;
    scanf("%d %d",&a,&b);
    int n = abs(a-b);

    int m;
    scanf("%d",&m);
    for(int i=1;i<=m;i++){
        scanf("%d",&arr[i]);
    }
    int dp[n+1];
    dp[0] = 0;
    for(int i=1;i<=n;i++)dp[i] = 2e9;

    for(int i=1;i<=m;i++){
        for(int j=1;j<=n;j++){
            if(j - arr[i] >= 0){
                dp[j] = min(dp[j],dp[j-arr[i]] + 1);
            }
        }
    }
/*  for(int i=0;i<=n;i++){
        printf("%d ",dp[i]);
    }
    printf("\n");*/
    printf("%d",(dp[n] == 2e9 ? -1 : dp[n]));
}