diff --git a/src/apple.c b/src/apple.c
index 766d543..28ad6be 100644
--- a/src/apple.c
+++ b/src/apple.c
@@ -4,6 +4,20 @@ int n;
 int k;
 int A[100000];
 
+int ringo(int A[], int n, int k, int x){
+  int i, count = 0, nokori;
+  for(i=0; i<n; i++){
+    nokori = A[i];
+    count++;
+    while(nokori-x>0){
+      nokori-=x;
+      count++;
+    }
+  }
+  if(count > k) return 0;
+  return 1;
+}
+      
 
 int main(){
   int i, lb, ub;
@@ -12,6 +26,19 @@ int main(){
     scanf("%d", &A[i]);
   }
 
+  lb = 0;
+  ub = 1000000000;
+  while(ub - lb > 1){
+    int mid = (lb + ub)/2;
+    if(ringo(A, n, k, mid)){
+    ub = mid;
+    }
+    else{
+    lb = mid;
+    }
+  }
+
+  printf("%u", ub);
 
   return 0;
 }
diff --git a/src/array.c b/src/array.c
index 13ed925..ffe7a26 100644
--- a/src/array.c
+++ b/src/array.c
@@ -4,15 +4,19 @@ int n;
 int k;
 int A[100000];
 
-
 int main(){
   int i, lb, ub;
   scanf("%d%d", &n, &k);
   for(i = 0; i < n; i++){
     scanf("%d", &A[i]);
   }
-
-
-
+  lb = -1;
+  ub = n;
+  while(ub - lb > 1){
+    int mid = (lb + ub)/2;
+    if(A[mid] >= k) ub = mid;
+    else lb = mid;
+  }
+  printf("%u", ub);
   return 0;
 }
diff --git a/src/spear.c b/src/spear.c
index 766d543..3962aae 100644
--- a/src/spear.c
+++ b/src/spear.c
@@ -4,6 +4,18 @@ int n;
 int k;
 int A[100000];
 
+int spear(int A[], int n, int k, int x){
+  int i, count = 0, nokori;
+  for(i=0; i<n; i++){
+    nokori = A[i];
+    while(nokori - x >= 0){
+      nokori-=x;
+      count++;
+    }
+  }
+  if(count >= k) return 0;
+  return 1;
+}
 
 int main(){
   int i, lb, ub;
@@ -12,6 +24,19 @@ int main(){
     scanf("%d", &A[i]);
   }
 
+  lb = 0;
+  ub = 1000000001;
+  while(ub - lb > 1){
+    int mid = (lb + ub)/2;
+    if(spear(A, n, k, mid)){
+    ub = mid;
+    }
+    else{
+    lb = mid;
+    }
+  }
+
+  printf("%u", lb);
 
   return 0;
 }
diff --git a/src/works.c b/src/works.c
index 766d543..1679b20 100644
--- a/src/works.c
+++ b/src/works.c
@@ -4,6 +4,30 @@ int n;
 int k;
 int A[100000];
 
+int worktimesum(int A[], int n){
+  int i, sum=0;
+  for(i=0; i<n; i++) sum+=A[i];
+  return sum;
+}
+
+int work(int A[], int n, int k, int x){
+  int i=0, count=0, timesum=0;
+  while(i<n){
+    if(A[i] > x) return 0;
+    else{
+      if(x - timesum >= A[i]){
+	timesum+=A[i];
+        i++;
+      }
+      else{
+	timesum = 0;
+	count++;
+      }
+    }
+  }
+  if(count >= k) return 0;
+  return 1;
+}
 
 int main(){
   int i, lb, ub;
@@ -12,6 +36,19 @@ int main(){
     scanf("%d", &A[i]);
   }
 
+  lb = 0;
+  ub = worktimesum(A, n);
+  while(ub - lb > 1){
+    int mid = (lb + ub)/2;
+    if(work(A, n, k, mid)){
+    ub = mid;
+    }
+    else{
+    lb = mid;
+    }
+  }
+
+  printf("%u", ub);
 
   return 0;
 }