```
class Solution {
public:
int coinChange(vector<int>& coins, int amount) {
int n = coins.size();
vector<int> dp(amount + 1, INT_MAX);
dp[0] = 0;
for(int i = 1; i <= amount; i ++){
for(int j = 0; j < n; j ++){
if(i - coins[j] >= 0 && dp[i-coins[j]] != INT_MAX){
dp[i] = min(dp[i], dp[i-coins[j]] + 1);
}
}
}
return dp[amount] == INT_MAX ? -1 : dp[amount];
}
};
```